I just found out recently that this one guy I genuinely liked wasn’t interested me at all or even really found me attractive just wanted me for sex? What should I do? Should I continue associating with him or just move on?
First, see if your information is correct. Did he ever express interest back? Or is this just an unrequited crush? If he had sex with you — and it sounds like he did — then he at least found you attractive enough to fuck. But that’s not the same thing as wanting to date you. If dating was your intention, and you communicated that to him, and he’s not interested, yes, it’s time to move on.
It’s OK for him (or anyone) to only want sex. If he led you to believe he wanted more, three things may be happening. One, you may have misread his signals and believed he was expressing interest in something more than sex when he wasn’t (some people are simply nice, and we tend to misread niceness as romantic interest). Two, he may have been genuinely been interested at one point but is not interested now. Or three, he may have been intentionally trying to fuck you over for fun, which sadly some guys do. In all three cases, you should move on, because he’s not interested, and there’s no point in continuing to pursue someone who isn’t pursuing you back.
If the sex was good and you’re OK with not pursuing anything further with him, consider making him a casual fuck friend. These are the best sex partners — the guys you enjoy being around but who want nothing more than sex. You never have to talk about problems or heavy stuff or remember his birthday, and you can fall in and out of communication without any sense of obligation.
Then again, if you’re really interested in him as more than a casual sex partner, I advise against it. If he’s not interested now, he won’t be interested in the future, so waiting around through repeat sex sessions for him to “come around” is just going to hurt you in the end. Move on — there are more guys out there.
It sounds like you might be young and new to this, so heads up: There will be a lot of guys you’re interested in who aren’t interested back. Get comfortable tossing them into the discard pile. Don’t hold on to used toys.