Struggling with Mental Health and Attachment Issues

I feel like I have more than just PTSD, anxiety, depression and all of that (ADHD + autism). I've been taking note on how volatile my outbursts can be, the three stages of anxiety, anger and then some odd sense of euphoria and recklessness. It's starting to scare me a little as well and it's always triggered by something traumatic in my past (i.e. my abuser that I've blocked trying to reach out to my friends). I've also noticed how attached I get to a particular friend of mine, he was there for me through all of the stuff my abuser put him and me through and we both pretty much empowered each other to get out of there. Whenever he talks to me, I feel immense joy and I'm always so happy to see him, but I always have the lingering feeling that I'm pushing him away slowly or that I'm just too weird for him, even though we have a similar sense of humor and such. Whenever he goes offline, I get extremely sad, I start feeling like I've driven him away or something along the lines of that. Whenever he's off for more than a few hours, I start getting more worried of that or that he's probably in danger. I hate having these thoughts. I have a boyfriend already and I don't like that I'm experiencing this attachment to my best friend, but I can't even stop it. I don't want to accidentally push him away because of how much I hate the attachment too.