I'm 22 and never dated..whats wrong with me?

Ok, so yes guys hit on me...but noneeeeeee where to be taken seriously. All my friends have been in serious relationships, and i do mean all ! So im feeling sooo lonely ...and the thing that sucks the most now is that if a guy i do like comes around...i would totally get nervous because i wont know how to make out with him...or show him a good time in bed :(..i just really hate where i am. I feel soo lonely and depressed all the time ..and most of all pathetic..i know im not the prettiest, but i don't think im absolutely hideous either..and i do work on improving my self everyday ..i dont know what more i can do..any advise? And i do go clubbing and partying all the time..but clearly no luck :(