'I couldn't stop obsessing over my toxic ex boyfriend. Then I learned there was a name for it.'

When Cassie* first met Ben*, she was in her twenties, dancing to the Sex Pistols in a sticky nightclub. "He approached me on the dance floor," she recalled. "I never forgot about him. Even when I was with other partners, I really felt he was special."

Many years later, they reconnected, and this time, it was intense. "He was creative, smart, kind, fun… just gorgeous. I really thought I'd hit the jackpot."

They became inseparable.

"We were joined at the hip. Our day-to-day life was domesticated bliss. We travelled all the time, overseas and interstate. We cared for family together, we liked the same music, had the same values. I really thought we were forever," Cassie said.

Watch: BAYH | Toxic Relationships. Article continues after the video.

Cassie believed she'd finally found lasting love. "He was so patient and loving. I finally felt like I'd won the relationship lottery," she said.

But under the surface, something wasn't right. And it didn't take long to show.

"Within the first three months, we were on holiday and I took a photo of a local man. Ben spiralled. He was so wounded, so jealous… it was like I'd cheated on him. I didn't realise it then, but that was the beginning," Cassie recalled.

What followed were years of obsessive jealousy, emotional shutdowns, and escalating conflict.

There were the outbursts, the accusations, the silences after nightmares in which Cassie had betrayed him — while he slept.

Still, she stayed.

"I did everything I could to understand him. I trawled the internet, read books, listened to podcasts, even saw my old psychiatrist just to talk about Ben's behaviour. I wasn't trying to fix him. I was trying to help myself cope," she said.

But it was exhausting. Over time, their intimacy dissolved. They stopped kissing. Stopped cuddling. Stopped sleeping in the same bed. Cassie tried to hold it all together — telling herself that if she could just stay calm, avoid triggering him, things might settle. But they didn't.

"I felt trapped, to be honest. I was crying myself to sleep most nights. I kept notes after every fight to make sense of it all, just so I could try and keep a grip on reality."

Then one night, something snapped.

"It was quiet. We weren't even fighting. He mentioned therapy, just in passing, and something in me broke. I screamed, 'I cannot do this anymore. I cannot be in this relationship.' It wasn't planned, it just came out," she said.

He didn't leave, so she called the police. "He left as soon as I dialled, thank goodness. But it was awful."

Still, she grieved. Not just the loss of him, but the loss of everything they'd built. The shared memories, the inside jokes, the version of him that had once been loving and safe.

"I desperately missed him," she said. "I cried and cried and cried every day. Sometimes sobbing so hard in the car I'd have to pull over. Spontaneous sobbing while trying to buy a croissant at a market."

When they crossed paths, he ran away. "Like I was the one who traumatised him." His family rejected her too.

That's when the obsessive thoughts took over.

The churning stomach, the intrusive images, the constant mental replays of what she said, what he said, what she wished she'd said.

"The first 18 months after the split, he was the first thing I thought about when I woke up, and the last thing I thought about when I went to sleep. Unless I was extremely preoccupied, like when I was at work, he was in my brain 100,000 per cent."

Even now, two years later, the thoughts creep in. Some days more than others.

"The past two days have been awful," she admitted. "It feels invasive. Compulsive. And it's secret. No-one but me knows those thoughts are going."

She tried to eliminate the triggers. She hid his photos on her phone and gave away items she associated with him. But some memories were too deeply embedded. Holidays, inside jokes, his "beautiful, smiling" face.

"I get angry at my brain," she said. "I'll catch myself thinking about him and say out loud, 'STOP.' But the thoughts creep back in. It's like my brain is holding on to him, even though I don't want to."

She knows looking him up online won't help. But sometimes she still does it. "Probably once a week. It doesn't serve me well."

Songs. Places. Phrases. Facebook memories. "There are so many triggers. I even had to tell Apple to 'show less of this person' in my photos."

She writes unsent letters, replays old arguments, fantasises about him apologising, wonders what he's told his mother and son.

"The worst part," she explained, "is that no-one really knows how bad it was. Because it was so private. So insidious. Even now, I feel embarrassed. Ashamed, even. Like people wouldn't understand."

That's when Cassie came across the word that finally gave shape to everything she'd been experiencing: limerence.

"It comes out of nowhere."

According to psychologist Orly Miller, limerence is more common, and more misunderstood, than most people think.

"Limerence is a psychological state that is categorised by intense longing for a specific person, obsessive thoughts, compulsive fantasies and behaviours, and a deep desire for emotional reciprocation," Miller said.

"It is as if you have been hit by Cupid's arrow. It comes out of nowhere. It's sudden and overwhelming. It's more powerful than a crush and has a lot of depth to it."

While limerence might feel like love—exhilarating, addictive, all-consuming—it's not the same thing. And it's not always healthy.

"Limerence is different from a crush because of its intensity and its impact on mental health and general functioning," Miller explained. "Unlike a crush, limerence becomes central to a person's psyche, affecting their thoughts, emotions, behaviours, and self-concept."

At its core, limerence is defined by "deep longing for closeness with a specific person, obsessive thoughts about them, intrusive fantasies, a strong desire for emotional reciprocation, and compulsive behaviours aimed at soothing the longing." It also involves emotional volatility—feeling elated when you think they like you back, then devastated when they seem distant—and a tendency to idealise the person to almost unrealistic levels.

While many associate limerence with unrequited love, Miller notes that "limerence can be either unrequited or mutual." And despite often having a romantic or sexual element, it's not necessarily about sex.

"Limerence is not always sexual or romantic, though it often includes a sexual component or undercurrent."

So why does it happen? That's still being studied, but Miller says there are early links to "trauma, OCD, addiction, and attachment dynamics." In her upcoming book, she delves into how early relational patterns and unmet emotional needs may shape the experience.

When love becomes a psychological trap.

The biggest danger of limerence is the toll it can take on your life.

"At its most acute, limerence greatly impacts a person's functioning," Miller said. "As more attention is involuntarily directed toward the desired other during limerence, focus on work, other relationships, and self-development becomes increasingly difficult."

This distress is often intensified by a lack of awareness. "The lack of awareness about limerence as a psychological issue and the stigma attached to the experience further exacerbates suffering and impairs relationships, self-esteem, and basic functioning."

Limerence becomes unhealthy when it causes significant emotional distress or begins to interfere with a person's ability to function in daily life.

According to Miller, society's lack of understanding about limerence is, in part, because culture and media blur the lines.

"I have a chapter in my book exploring what I call the 'legacy of limerence,' which refers to the media and artistic representations of love throughout history and into modern times that have shaped our collective views on what love is," she explained.

"These portrayals often idealise core features of limerence, making it more difficult to recognise as a psychological state. They tend to blur the line between love and limerence, making it harder to see limerence for what it truly is."

"You are not broken. But you are suffering."

Miller wants people to know that limerence is real, it's serious, but with support, it's treatable.

"The first thing I wish people understood about limerence is that it is a unique psychological experience, marked by a distinct constellation of symptoms. It is something we need to take more seriously, study more deeply, and respond to with thoughtful and empathetic interventions."

For anyone reading this who suspects they might be stuck in it right now, Miller has this message:

"You are not broken. But you are suffering. Support is available. Healing and transformation are possible."

"I remind myself: this is just limerence."

Cassie now knows that what she was experiencing wasn't just grief, it was limerence. 

"It explained everything," she said. "It was very liberating… it meant I had a choice. To direct my energy somewhere else. I remind myself: this is just limerence. You are limerancing. It's just a thought giving you emotions. You can control emotions through thought." 

She's also worked hard in therapy to get to the root of her issues, and analyse her patterns.  

She also recognises the role hope played in keeping her trapped. "I kept hoping. Kept imagining these volatile events would stop. Or lessen. I felt tied to him by hope." 

Cassie says she's "totally off the market" now and still feels jaded about love. But she wants others who might be stuck in the cycle of limerence to understand one thing. 

"This is not about them. It's about you. That person is not your penguin, or your new best friend. Work on yourself. Give yourself that love and attention. You are giving way too much energy away with limerence." 

*names have been changed.

Feature image: Getty. (Stock image for illustrative purposes only).