Real Event, NEED advice

I have been dealing with POCD for years now. This past summer, something happened that I havent been able to get out of my mind. My friends and I were in the kitchen and my girlfriend was holding my niece behind me while I was washing dishes. I kept getting thoughts that I was being weird and exposing my niece to my butt. I kept saying that I wasn't trying to do so. But I shifted closer to her and I immediately felt guilty. I was like "why did I do that." This whole time I was trying to avoid it so why did it happen? I tired to tell myself that all of this wasn't true that I would never do something like that consciously or on purpose. But I knew i had done something wrong. I tried to remember as soon as it happened, but I could no longer remember how it even happened. But when I got a sudden thought of "no I didn't do it with bad intentions " I got so much relief. But then it would switch again to me having done something wrong and I'd feel guilty again. I tried convincing myself I did nothing wrong and forgot about this incident. A couple of months ago it came back to mind. I immediately felt panic and guilt. I tried convincing myself I did nothing wrong but I knew that I had in fact shifted my body closer that I had done something. But i just couldn't believe that i would've done something like that. once again I'd get a random memory flashback that I had no ill intentions and I'd feel relief. I kept trying to remember how it happened but I couldn't. I just knew I did something awful. I tried to explain what happened but I couldn't, but eventually I remembered that I had moved closer. I once again suppressed the memory and moved on. But it has once again come to haunt me. I try to remember the details but I cant. I just know that I did know I had done something and that I immediately felt guilty afterwards but when I try to remember details I cant. And I just don't understand this bc I'm always so cautious. I something close my eyes when I see pictures of my niece, or I'll put my hands in fists when I'm next to her bc of my urges, and when they make me hold her and I have an urge it feels terrifying. As of now the thoughts have decreased around her but now im scared to get her contaminated.