My anxiety is ruining my relationship

Hi. I'm looking for someone to talk to because I feel like I'm stuck in a cycle that I don't know how to break.

I'm autistic, and I struggle with severe anxiety around relationships. Once I become attached to someone, I become terrified of losing them. I constantly worry that they'll leave me, cheat on me, or stop loving me. Even small things can trigger those fears, and when they do, my mind jumps to the worst possible conclusion.

My current relationship has become really difficult because there have been things that genuinely damaged my trust, including dishonesty and broken promises. Since then, I've found it extremely hard to trust again. Even when my girlfriend reassures me, my anxiety keeps telling me something is wrong. I know reassurance can't fix everything, but in the moment my brain feels like it needs certainty.

Because of that, I end up asking a lot of questions, seeking reassurance, and sometimes wanting to check things. I know this is exhausting for my girlfriend, and I don't want to control her or isolate her from people. That's never been my goal. I just become so scared of losing her that my anxiety takes over, and I react before I can think clearly.

We've been arguing a lot because of this. She says she feels trapped, watched, and emotionally drained. I feel constantly scared and insecure. We both love each other, but we're both hurting. I don't want my anxiety to keep damaging the relationship.

Outside of my relationship, I also struggle with my mental health in general. My home life isn't great. I don't feel emotionally close to my parents, and I don't really have people I feel safe opening up to. My family doesn't take my mental health seriously, so I've mostly dealt with everything by myself.

When I become overwhelmed, I can panic badly. I cry a lot, my thoughts spiral, and I sometimes feel like my whole world is ending if I think someone I love is leaving me. I hate feeling this way, and afterwards I usually feel guilty and ashamed.

I don't want to keep living like this. I want to learn how to regulate my emotions, manage my anxiety, build healthy trust, communicate better, and stop depending on constant reassurance. I want to be able to have a healthy relationship without feeling like I'm always waiting for something bad to happen.

I'm here because I genuinely want to change. I'm willing to put in the work. I just don't really know where to start, and I'd really appreciate someone helping me understand why I react this way and what I can do to get better.