Advice on strong arousal to thoughts

So I was enjoying some “me time” and had intrusive thoughts, but it felt like just for a second I liked it. Like I’m holding myself back from “enjoying” the thought. And the thoughts are related to things I was into when I was younger, but sometimes I feel like I might still like it even though 9/10 I wouldn’t give it a second thought. Is this common? Or is this just denial? Thanks

Does anyone else when they have the thoughts, they feel against it, but they still get arousal or tenglings sensations in the groinal area? Because this is what I experienced today and I feel like crap. This is going to be very triggering for a lot of you, but there are a lot of times that I notice things from kids. For example, there is a thirteen year old kid who looks very developed for her age, and I take notice of (and this already sounds creepy to me) her chest. Today with my thoughts, I imagined as if I were touching it, and although I usually "no no or "I don't want to do that", she is a kid, etc., I still get responses in my groinal area, and It felt very real. Even now, I feel as though I am faking it, even though I groan 😮‍💨 from it, and feel as though I am a fraud. Does anyone relate?

How long should I do ERP, so that my brain gets used to it, not to say tired?! I've been working for about three months, but everything still seems vivid in my head, there are even vulgar words in detail... since the sexual topic is both a groinal and a feeling that I want to touch myself. It's mostly related to faces and genitals, so how exactly can that go, if it's emphasized that sex pictures in themselves give that feeling, whoever is in them?