Why can’t i stop thinking about thissss?

So lately I’ve been thinking about my ex crush from a few years ago and having sex dreams with him in it. It took me a long time to get over him and now we’re kinda becoming friends (we never talked years ago) and i don’t think I have a crush on him like the way I used to but I just wanna give him oral sex and do things with him and I’m 17 and never done any of those things... I had two dreams about it already and I cannot stop thinking about it like whenever I zone out it’s what I think about it’s soooo bad 😫 ig my thirst raging hormones are finally kicking in 🤦🏻‍♀️🤦🏻‍♀️🤦🏻‍♀️ what should I do about it?