Why are my thoughts getting more gross and disturbing

I need advice for intrusive thoughts. I used to feel like I could handle them. They weren’t nearly as bad as the things that related to my actual life. But now, I’m suffering. I haven’t had a sexual experience in over a year that didn’t involve constant intrusive thoughts. Most are somehow related to kids and I keep chasing off the thoughts but it’s so bad. I know you’re supposed to ignore them but I don’t know how I can just ignore that and continue what I’m doing. But they’re coming on stronger. I had one earlier I could not get rid of just as things finished so the thought came on strongly just before my orgasm hit and now I feel absolutely disgusting. I hated the thought and I know it’s not me and it was not enjoyable but it still feels like I was getting off to it. I feel sick. I’m so fucking tired of these thoughts. They’re in my every day life too and it’s all the time. I just want it to stop but ignoring it feels so wrong. What should I do?

I deal pretty heavily with this. The last couple days, I’ve had what I think are urges. Something pops into my head intrusively and then what stems from that is me WANTING to just indulge in it even though it’s gross. I get worried bc I used to struggle w thoughts about my dad for a long time until eventually I just purposely thought of him while self pleasuring and got off to it. While that’s something I did, it is NOT me. It all stemmed from my mental health declining a couple years back, I was never this way before. So I get worried that it almost happened or might happen with my pocd cuz I could never live with myself if it did.

Why are things so real the first time they’re in my mind and then when I think about it later it’s easier for me to be like wtf?? I was watching a movie earlier and the young girl had developed more in the chest area than the last movie and I felt the desire to check her out so I did. Then later I let myself imagine her having sex and I liked it. But now looking back I’m like ew. The boys in the movie have also developed as the movie went on and I couldn’t help but think that in their real life they’ve probably woken up to boners and s*men and stuff. And looking back it’s just ugh. Idk if it’s sexual relevance but I genuinely let myself indulge in these thoughts and groinal responses and I remember thinking to myself I don’t want to be attracted to little kids and how do I stop myself (everyone has attractive qualities so in younger boys I see man like qualities). Idk I need help. I wouldn’t type this out if I truly believe I was messed up but I’m still scared