Is it normal that i can only fall asleep to one thing

There’s this one thing I can fall asleep to, it’s just one specific scenario and I always think about to while falling asleep. But it’s not just that that worries me, it’s that while not being an erotic situation, sort of makes me... horny I guess? I don’t think it’s horny, it’s like a sharp/sudden feeling in my groin and lower stomach that comes once in a while (and is controlled mentally, so not random) and it feels nice but it’s quite sharp so if it happens too much it’ll hurt a little and I have no idea what it is if not erousal. Like, it won’t make me want to masterbate so I don’t think it’s horniness.

I tried to stop thinking about only this while falling asleep last night and I just stayed up thinking about “Can I not fall asleep without this??” “What if it’s some weird fetish??” “Why can’t I just fall asleep??” And only got like 4 hours of sleep, as compared to 8 hours ago every other night.

Should I not care so much? I don’t think of it during the day or while I masterbate, but the thought that maybe it’s sexual makes me think maybe I’m being an obsessive pervert. but I don’t know. It’s been bugging me all night and ever since I woke up.