Interesting. I don't think on my part it was obsessive, but I have had imaginary "crushes" but knowing full well it was in my imagination only.
I just assumed this kind of thing is normal. People have attractions to others but if someone is in a committed relationship they know to not ever act on that.
But reading this article, I can see how this could be a form of self soothing to imagine something happy and loving when there doesn't seem to be much of this at home growing up.
There was one guy I dated as a teen who I continued to have an "imaginary" crush on- after the relationship ended. I knew this was beyond the actual relationship which didn't last long and wasn't a serious one. I always wondered why that was. We went to college miles apart and had little contact after that.
I don't have that "crush" now- haven't for a long time but I can see why I held on to it. I wasn't getting the kind of love and attention a teen should have from their parents, and home life wasn't safe or stable, and in the middle of all of this was someone who liked me, and acted towards me in a caring way, even if just for a brief time.
I think the continued "crush" became a way to deal with difficult feelings or a situation- so as you said a sort of "drug". While the article frames it as a disordered thing, I see it differently unless it gets to the point of being obsessive and disruptive. It may be a form of resilience to imagine something good and happy when feeling anxious or stressed. If we aren't getting the kind of love and attention from our parents, thinking about someone who cares for us might be a positive way to cope.
I think it's common for children and teens to "get stuck" developmentally when there's family trauma or parentification. This could be something like indulging the "inner child". It's common for teens to have imaginary crushes, on pop stars, or actors. These are "safe" crushes- there's no way they'd ever be real.
The important part is to see it as it is- in the imagination and never to be acted on. It has nothing to do with another person, or one's own marriage, or anything real. It's a coping mechanism. The approach would be to learn other ways to cope.
I agree with you Notwendy, and had imaginary crushes myself too growing up. Nothing wrong with that.
With this guy specifically though, I remember it got completely out of hands. I was completely addicted to him. I think he also triggered my abandonment trauma. The energy between us was something I had never felt before, like a trauma bond before trauma happened... it was out of this world, more than butterflies just an electric buzz that simply wouldn't fade. But it was nervous, full of adrenaline, not soothing like my love for H feels. Reading on the hormones generated by limerence as opposed to love, it all makes so much sense now. In comparison, meeting H felt flat, not because I wasn't excited, but because everything felt flat in comparison of the energy I had with this guy.
He made me feel high anytime he was around. It wasn't lust either, partly, but most of all it felt like such a deep connection. And when he moved elsewhere, we kept texting and calling each other, and it was a fix, every single time. I'd be thinking and talking about him all the time. But it was more than your usual infatuation, or imaginary crush. It felt deeper, so very real, like we were meant to be, and I would long for him... All the while knowing, very well rationally that : I didn't know him AND he was kind of a dick too to me...? He told me later he always thought we'd end up together too, and it just made my limerence worst. Maybe he was limerent for me as well, who knows, but it wasn't healthy. It never went further than flirting, longing and a kiss though... yet I dreamt of him for 6 years almost every night.
I hear you for imaginary crushes... I guess limerence is when the imaginary crushes become obsessive... I had many crushes that never developed into full blown limerence. With him, it did though. Just yesterday, he answered a professional email I sent him, and my heart skipped a beat. And I am aware how inappropriate this is. I know I have OCD traits, I learned those as ways to cope growing up... My brother became an addict, there are a lot of addicted people in my family...
It just makes sense...
The only way I found so far to decrease those obsessive thoughts are to stay away from him and to heal myself, increase my self-awareness, make an extra effort to remain connected to my husband... But it is just weird to think that you can be addicted to a person like you would be to a drug... And it makes much more sense than to think he is a soulmate or a twin flame or other reincarnation magical thinking...
I scare myself honestly... Imagine being on the receiving end of limerence? I must have looked completely crazy at times !

I thought maybe someone here would have experienced this too, as it seems to be linked to emotional abuse, parentification, neglect and abandonment trauma growing up.