Friendships - genuine ones! - take time to build & mature. You need to find people with common interests, common ground - always the best basis for any type of relationship. In elementary & high school (unless your family moved really often), you built relationships over years! You expect instant-attraction? Doesn't work that way, especially as an adult now. You give up too soon, too easily.
What are your interests, your hobbies? What do you like to do? Ski buff (or ski bum), join the ski club. You're a shutterbug? Join photography club. Majoring in communications/media? Get involved with student publications, radio/TV, etc.
Get your head out of your butt, get off your self-pity & GIVE. Volunteer for a student-run service/charitable organization. Volunteer in the community. Get busy & stay busy. If you care about others, they'll start caring about you.