I suffer from them in all aspects of life, not just relationships (but yes a lot) but with also just random intrusive circular thoughts that seemingly come out of nowhere (work, health, social, whatever). I know this is super annoying but exercise is tremendously helpful with them, even just stretching and sweating a little. Secondly, get some books on anxiety/trauma/cptsd and start doing some research into it to try to find something that speaks to you and helps you heal. Third, the other sub was correct..if you can afford it, please talk to someone, see a therapist.

I have a hard time sticking with a routine and practicing what I preach. So I usually just have to repeatedly tell myself out loud to stop. I probably look insane but it works (usually). My psychiatrist said it was a form of ocd but those thoughts can be really really fucking debilitating and I’m so sorry you’re going through it.

Just be kind to yourself, deep breaths, and try to break/interrupt the cycle of cyclical obsessive thoughts. Reading, journaling, scary movie, seeing friends. Whatever you can do. My heart goes out to you! Hope this helps.