So i've got little experience in kissing?

Ok I'm 18 and have only had two boyfriends one when i was 14 and the other when i was 17, I've only kissed one (the other one always had some nasty hy stuff in the corners of his mouth and that really disgusted me.) Consequently i don't have much experience with kissing. I'm always terrified that someone will think I'm a bad kisser. That always leads to me pushing guys who like me away, because I'm very ashamed of this fact. I'm tired of pushing people away, what should i do to resolve this problem?