Obsessive thoughts over another person- any advice?
So for a long time i've (F18) been having obsessive, pretty much daily thoughts about a person (X19) I have/had a difficult relationship with. The situation was complicated, but I finally completely blocked this person about a year ago and cut off all contact- and I haven't even seen this person in real life in 5 or 6 years. But they're the only thing I seem to think about. It's not really romantic, and I definitely have negative feelings on it, but platonic is not a strong enough word for what went on. I won't go into details, but it just feels terrible. Every day I have at least one daydream about what it would be like to see them again in public. I make up scenarios where we find each other again. I have to continually restrain myself from googling their name, or impulsively making contact. I have about a million submissions to the Unsent Project directed at this person.
Today I had a moment of weakness and searched their name on Indeed, and I found them. I saw their face again in the profile picture and I was stunned for a half hour. I immediately closed the tab, but it's burned into the back of my eyelids. I feel really crazy, and I know I shouldn't say that about myself but it's all I know. I tried googling about clinical examples of obsessions over people but they're all so romantic and so stalker-like, "erotomania" and "limerence" and stuff like that. I'm pretty sure this person feels a similar way- they've said as much, since we last spoke, and they've been diagnosed with schizophrenic delusions before, which sort of contributed to the situation we were in, but part of me feels like maybe I'm just making it up, like I'M the delusional one. I have great friends and a wonderful girlfriend, but no bond I make feels as strong as the one I have with a ghost from my past, which feels awful to say since I DO love my girlfriend. We're celebrating three years soon and I'm the asshole who can't stop thinking about my middle school best friend.
I know this comes off like a vent, but my question is, has anyone else ever dealt with an obsession like this, or read about it in a clinical context that wasn't "he loved her so much he stabbed her" ?? Everything i've read is just OCD and other disorders with no overlapping symptoms. Should I just keep trusting that time will heal??