Am I okay??

I’m 18 and I’ve never had a boyfriend, and the last time I’ve had a crush on someone was 4 years ago. I don’t really get feelings for people easily and I’m not sure if it’s more to protect myself or what. I talk to guys but it never lasts more than a couple weeks. I’m not sure if there’s actually something wrong with me that makes people not want to stick around? I’d like to think I’m a really nice person, can be funny, and I’m conventionally pretty. I’m confident in myself but seeing all my friends falling for people and getting into relationships is really making me second guess myself. This is probably stupid but I wasn’t sure if someone else has been through something similar. I’m terrified I’ll end up alone or have to settle for less than I think I deserve and be unhappy :/