Feel like I cheated and need help w guilt

Tw. My post contains talk of porn/sexual themes, and fear of cheating. So I have rocd and some hocd. My hocd usually related to my rocd, but rocd is my biggest theme I deal with. So a couple of days ago I was on Twitter and I saw erotic things. I got curious and scrolled on the accounts. My body had a physical reaction to the problem and I was like "so my body had a reaction so that means I need to conduct my business". This is highly unusual to me because I absolutely DESPISE porn. I dont actively seek out porn or to look at other people so this reaction my body had was distressing. I don't look for porn for pleasure because i think it's very bad for the brain. Anyways I thought I pleased myself to porn and it scared me (even though I was thinking about what me and my boyfriend could do when i watched the videos). It wasn't a huge deal until yesterday. I got hocd thoughts and I had the compulsion idea of "maybe I should download Twitter again and look at lesbian porn to see if I'm gay". Of course I got curious and my body had a physical reaction. Same events repeated.. my boyfriend was in my mind when I conducted business. Now I feel extremely guilty. Not that I did it once but twice. I talked with my boyfriend last night and he said he considers watching porn cheating. He said actively seeking out and watching is cheating but... i genuinely cant tell if i actively seeked it out or not. Now I believe I cheated and I feel the urge to confess constantly. I feel horrible. I feel like I betrayed the love of my life. I have no desire to watch porn and please myself to the porn. I would rather please myself to him but I feel so guilty that I did it twice. Both were slip-up's. I don't think it was my genuine intention to seek porn and jerk off. I just reacted to my bodys reaction twice and now i feel like I cheated. Now when I talk to my boyfriend I feel anxious and remember my guilt (classic rocd). Advice on how to deal with this? Can someone give me adivce on how to navigate the guilt. I genuinely can't tell if I've crossed a boundary with my boyfriend and should tell him or not to avoid confessing. It feels so impossible to live with guilt of thinking I cheated. I need advice on how to deal with it. No reassurance please.