Obsession to self-sabotage?

[Cazzles]

Wasn't sure where to post this tbh - sorry!
So as like many people no doubt here, I am consistently hesitant to trust; partners, family or friends.
I've been with my OH for 8 years nearly, love him dearly, most of the time. But as I'm discovering more about my CPTSD, and how i react, I'm starting to resent him. I don't know why exactly.
And an old friend popped up during Lockdown which was totally unexpected; having stopped talking a few years before because we conflicted has made me have some super strange feelings.
This old friend - I have never met him - we met on a teenchat room when I was like 15 (dangerous I know) and he was 14, and we have been speaking on and off for the last 14 years... He has always said that he has forever been in love with me (unbelievable to me), and still he knows he will likely never meet me. I am from UK and he lives in Canada - pretty far away!
He and my OH are aware of each other, and I'd like to continue with my OH completely. But lately with being hyper emotional to everything, dropping friends like potatoes etc, I am finding myself OBSESSED with my old friend. But i don't want to be. Its like a totally new emotion that I can't control.
I'd like to continue as I was but rekindling with a friend not like a crush - and drop this teenage obsession before i buy a diary to hide under my pillow.
Has anyone else experienced this?