feeling worthless

i know this has probably been talked about a lot but i'm beginning to feel like i will never have a close connection with someone, besides sex. all guys want nowadays is sex and no one wants to be committed. it makes me think something's wrong with me. most of my friends are finding guys worth their time and someone who wants to *be* with them, but i'm here all by my lonesome. don't get me wrong, i enjoy my own company, but seeing everyone else makes me very insecure and i go back and forth with myself about it. does anyone have any advice on how to get past this? i'm only 20 and i feel like complete shit.