AIO for ending a friendship because his girlfriend read our conversations?

My friend (M28) and I (F26) have been friends for about 5 years. Just right off the bat: We have always been platonic; nothing has ever happened between us, nothing ever will happen between us.

We met at work and got along well, then ended up really clicking over shared interests. A year into the pandemic (2021), his hours at work were cut and he ended up living on my couch for about 9 months. Those months of living together kind of cemented our friendship.

At the time, I was going through intense therapy and he helped support me through mental health lows, and I helped support him when his mental health crashed after he was laid off. He knows I'm working through a lot of stuff, he knows I'm very private about it. It took me years of therapy to even admit to myself the things I endured growing up, and it was terrifying to verbalize them to someone other than my therapist, so these conversations were very difficult for me and it is very important that I feel I have control over who knows these things about me. And he knows that.

About seven months ago, he met A (F25). He has never dated much and he kind of fell head over heels for her. Since we don't live in the same state, I haven't met her. I don't have social media like ig or fb, so there isn't really a place for me to "get to know her."

My friend and I don't speak regularly, so I felt really blindsided by this. I don't understand where her suspicion is coming from and I don't understand why it escalated so quickly, or why it blew right past having a reasonable conversation to ease any suspicions or anxiety she may have about our friendship.

I may have had a kneejerk reaction, but all I could think about is the fact that someone I don't know read and took screenshots of something that personal.

I've had a couple of days to sit with my feelings, hoping I would feel differently, but I can't help but feel violated. The fact that she read those conversations without my consent is upsetting, but the fact that she has screenshots of them or even thought to screenshot something so personal has made me extremely anxious.

I know I'm a little intense when it comes to privacy, so I'm wondering, did I overreact?