Learning not to act on compulsions (longer read)

I'm pretty new here but through a string of events I now am trying to learn how to deal with my OCD better! I've been through quite a bit in my life, including emotional neglect, physical and emotional abuse in relationships,etc which I guess is somewhat common. I just didn't realise until a couple of years ago (thanks to therapy) how bad it has impacted me and how I deal with things. My last relationship went pretty badly because the man I was with turned out to be very emotionally abusive; when he got angry he would simply ignore me, sometimes up to a week and he got angry a lot for the smallest things; he'd get upset when i didnt reply to him fast enough or when i shared my feelings when he hurt me in any way; he'd fully stonewall me which made communication awful and then he'd love bomb me later. All of it left me pretty unsettled and mistrusting of people and I thought it would take me a long while until I would be okay to meet someone new again... but well, I met someone at the beginning of the year and we became great friends and are now more than that. We haven't given it an actual label yet and I'm glad he's giving me time and patience because that's something I never got in my previous relationship even though I had asked for it (go figure). The issue and the thing where my ruminating and checking compulsion comes in is that he likes to roleplay in a video game we both play. Now, we had a chat about it where he reassured me and told me that it was all fully in character and just a creative outlet for him, which I get. He even asked me if I wanted him to stop but I told him that's not my place and I'm not going to ask him to stop engaging in a hobby because I wouldn't want him to do that to me either. And I mean it. On most days I'm fine. I know he'd drop everything if I needed him and we spend every day together. I'm glad he has friends and things going on in his life but when I'm overall stressed (I have a demanding job and issues with sleep and anxiety in general) I start ruminating and spiraling so bad and the thing that I often act on is checking what he's doing in the game and who he's hanging out with and I feel embarrassed for it. I wouldn't want him to do that roo me so why is it so hard for me to stop? I'm so scared of getting replaced, of him suddenly changing his mind, that I perceive other people as a threat but checking over and over doesn't help either. It doesn't give me actual control over the situation it just makes me feel ashamed and sad but I keep going back to it the second I feel somewhat insecure. He has done nothing but be absolutely lovely, understanding, considerate, communicative, etc... which makes me feel even worse when I act on the compulsions :( I'm proud how far I've come and that I'm at least trying to get better and recognising the patterns but I'm also exhausted :/ I don't want to self sabotage (I tend to become bitey and avoidant when triggered) because I think this guy is actually great and he makes me want to be better! Anyway thank you for reading and sorry for the wall of text! It feels good getting it out :')