obsessed with a person

First question, does anyone have OCD and BPD? How did you go about getting diagnosed and what were the signs you were dealing with both? I feel as though there be something else going on but I’m not sure and I don’t know how to address this as I’ve never been flagged and I have no therapist nor psychiatrist. I’ve been briefly screened a couple times and diagnosed with OCD, GAD, and MDD, so I’m medicated (which I’ve been off for months so currently not medicated) through the PCP (as in they manage treatment but can’t do much beyond prescriptions) but I feel like I might have something else. You may be wondering what this has to do with relationships. Well I feel like I’ve developed a strange attachment to a new friend and so I’ve distanced myself for both of our sake but my mind keeps going back to them. I think of them constantly and see that their presence in my life has impact my behavior, like style of speaking and interests, like I need to adopt their personality to be liked by them because I like them. It’s also a strange predicament for various reasons but I’m scared to lose this person. I don’t know what to do or how to explain it. I am for a lack of better words “obsessed” with them, ruminating over our every interaction and what I said or did and how they reacted and whether they still like me. I will ignore them for days, not because I don’t want to talk because I really want to, but once I start I can’t stop, I need to detach before it escalates and I can’t go back. But when I see their notification despite my absence, it’s like everything lights up and my mood is dependent on whether they acknowledge me or not. It’s not healthy. There’s more to it… so much more… but I don’t know what to do. I can’t tell if I’m mirroring them or not, I feel like I’m losing myself. It’s almost that question of “do you want to be them or be with them” and I think it’s a mix of jealousy, admiration, insecurity, and honestly feelings that are more than platonic and I need to get out of it now. I can’t afford to love them but I also can’t lose them, they suddenly feel very important and this is all so unfair to them but I can’t explain what’s in my head or it’ll drive them away I fear. How to stop obsessing over someone and establish a healthy relationship?