I'm still having random thoughts about my ex after 1 year,I have a gf and its uncomfortable what is happening to me? I'm not happy I think I'm broken

My ex boyfriend broke up with me last summer and it was really rough on me even thought we only dated for a little while. He treated me terribly but I guess I wanted it to work. However during the fall I was healing well and met my current boyfriend. I knew him as a kid and we reconnected and started dating. It’s the most WONDERFUL relationship ever and I love him so much. However for the past couple months, on and off, I have been obsessively thinking about my ex, to the point of feeling so sick to my stomach. Just the thought will do it. I have been stopping myself from checking his instagram because that just makes it worse. I do not want me ex back at all and I am so happy now. I recognize these thoughts as intrusive and hurtful. I just want them to stop and be in the moment. Has anyone had a similar experience? What did u do? Also, I want to tell my boyfriend about this but I am unsure on how to do so.

I feel like I really need help right now. I keep reminiscing on my old relationship and comparing it to my current one. For context, within my old relationship I had been with him for a pretty awful year and 3 months. Within the first 3 months I realized that I didn't actually want to be with him, but I felt sorry for him. So, I stupidly started self sabotaging the relationship. I know that it was stupid, and I tried to break up with him but every time I felt bad. His mental health was already bad and I hate any possibility that I can make someone's mental health worse. That whole "relationship" was so toxic on both ends though. All of that alone has me so messed up. But with that I also had this false attraction to him. Like, I would always be figuring out what I wanted in a relationship and tried to do that with him despite knowing that I didn't actually want to be with him. Now my mind keeps trying to convince me that I'm doing that with my current relationship. I know that I'm not. This one feels genuine and it's pretty healthy. We have our bumps, but we both have this want to fix it and it's just so nice. I hate that my brain is trying to ruin this for me.

I met my current boyfriend after ending things with my ex a month earlier. By coincidence, my current boyfriend and I had a class together, we became friends, and of course I started liking him. By May 2021, two months later, my feelings for him grew stronger and stronger. At that time, I wasn’t really going through a depression over my ex. In fact, little by little, we had stopped talking since January 2021, and by the end of March I told him I needed my personal space because I was dealing with another type of OCD. Looking back, during all that time I was open to getting to know this new guy (my current boyfriend). Finally, in July everything was going well between us, and we decided to stop giving each other space. Meanwhile, my ex was stalking me on social media. I was very happy to be getting to know my boyfriend at that time. In August, we had our first kiss and then, as I mentioned earlier, we stopped dating for a while. In September, we ended things, which hurt me a lot, but in November we tried again. During all that time, I didn’t have OCD. Later, in January, when my boyfriend and I made our relationship official, the doubts started: “Am I still in love with my ex?” “Am I using my boyfriend to forget my ex?” “Am I really over my ex?” The memories, physical sensations, all of that. So, my question is: does OCD with thoughts about an ex only happen to people who just broke up and are still grieving, or can it also show up later on, even if you’re already in a new relationship? I ask this because I’m afraid I might not have gotten over my ex and that these intrusive thoughts mean something else, since I’ve read that some people develop OCD right after a breakup and get stuck there. But in my case, I just moved on, and then the intrusive thoughts showed up later.