I'm in agreement with the other responses so far (especially divine). Obviously it's very easy for other people to say, but there are things in life apart from relationships.

I can't give much actual advice when it comes to dating, but I like to think I'm ok at finding other stuff to do with my time. When you get to your 20s, it may seem like a lot of people you know are already starting to settle down and have serious relationships (and that's fine), but don't let it trouble you if it hasn't happened to you yet. There's so much stuff going on elsewhere. You can do so much - experience things you've never done, do new stuff, see new places, meet new people. If you keep yourself busy doing stuff you want to do, not only will you be (hopefully) having a good time in your life, but the act of seeking new interests may broaden your horizons and help you connect with people in a way you hadn't thought possible before.

It feels like I'm just spouting off cliches, but there are several things here I've had to take to heart myself - I've beaten myself up a lot thinking "there must be something wrong with me, because I'm not in a relationship", but it's just one of those things. You have to wait it out, look after yourself and things will work out in the end.

Apologies if I'm just telling you stuff you already know; these are just my thoughts. Good luck!