Advice on how to manage relationship ocd

I'm currently in a relationship and i have been for about 3 months now, so far, our only conflicts have been consistently connected to my ocd. (let me explain) I was diagnosed with ocd as a child, and it is something i have lived with for most of my life. My obsessive compulsions have obviously changed over the years but were mostly externally manifested (contamination, rituals, etc.) Becuase of this, and extensive therapy I have become very good at managing it and thought I had it under control. It was not until recently that i began to notice more of the mental, internal loops. So this is still very new to me. When I first met my boyfriend I had th same issue a lot of people seem to have with relationship ocd where i would spend so much time obsessing over his negative traits or over analyzing them out of fear of him not being right for me. I didn't see this as an ocd pattern then though, which I think is what led me to a bit of a "slip" in terms of my ocd management. That eventually faded after about a month but once my brain accepted that this man was indeed the "perfect" man then my obsessive thoughts shifted towards needing to act perfectly in order to never make a mistake and make sure I don't lose him. Most recently, a conflict arose because I was having lots of intrusive thoughts convincing me that I was being unfaithful because I found someone else attractive (even though I had 0 interest in pursuing them and did nothing towards that) The thoughts got so bad I lost my appetite because of how bad my stomach was in a knot from the guilt. He obviously noticed and then got suspicious and when he asked me what went down during my interaction with the person I found attractive I ended up lying about a minuscule random detail because I was convinced I had done something wrong even though again, that was not the case. He got even more suspicious and mad because I had obviously lied and then once he forgave me and let it go he kept saying "I just don't understand why you feel so guilty if you really did nothing to feel guilty about" This left me frustrated because I could clearly see I had hurt him and because it was for the stupidest reason, because I had built up an imaginary scenario in my head and convinced myself it was real. I tried to explain the intrusive thought thing but found it difficult to get my point across without it sounding like a petty excuse. Basically, I just want to know how to talk to my partner about this, navigate it or whatever else I should do to ensure conflicts like this don't happen again because I really like this man and I would be so mad at myself for ruining it like this. I want to stop the obsessive thoughts before they get worse.