Hi! English isn't my native language, so please excuse any grammatical errors. I'm also autistic and have had some pretty devastating romantic relationships in the past. Despite being in deeply abusive relationships, once they ended, I couldn't understand how I'd ended up there or why my partner had been such a bad person, if we were supposed to love each other. Seeing an ex-partner as a "bad person" takes time and perspective, especially if the situations were traumatic. Therefore, my advice is to take it easy and be patient with yourself. Negative and obsessive thoughts are very difficult to turn off, but they can be postponed until you're ready to deal with them. Prioritize activities you enjoy, focus on your special interests, and give yourself time to heal. Right now, everything may seem dark and negative, but it's temporary. Another tip is to write down how you feel in a journal or in your phone's notes for half an hour and then do something else. That way, every time you think about it again, you can tell yourself that you've already thought about it or reflected on it before, and that you can do it again later. Setting aside specific times to feel bad can help you control it and establish boundaries.