I'm twenty years old and just got back into college. My freshman year was horrible, I made a lot of bad choices and failed a few courses. After taking a year off and a few community college courses I re-enrolled in a university. Now I'm there, been three months, I have an apartment and am doing well in classes. I used to do a lot of drugs, but now I only smoke pot. I used to be fat as well, lost a lot of weight and run daily. Thing is, I haven't made one friend at all. I drive to campus, walk across campus, go to my classes, and then it's back to the car. I smile and make eye contact with people, I just never know how to talk to them. In class I haven't talked to many people, and when I do they usually just talk about the work we are assigned and the conversation is over. So lately I've been just smoking pretty much around the clock, when I wake up, before I run, after I run, during homework. I still have all A's and B's, I guess I'm just depressed as hell that I have no friends. It's college, people are supposed to party and be open, right?
Generally college is like that but it's not a one way street. You have to be open too! Try to strike up a conversation with people. My mom used to tell me to not talk to strangers and keep to myself but when I entered the college world I learned that was no way to get to know people. Just ask where there from and what they do after school just regular chit chat and see if they want to hang out with you.
There are few people in the world who will take the initiative to befriend a stranger so if no one is talking to you then talk to them! ^_^
Another thing you should consider doing is thinking about joining a campus organization. You will be with others who have the same interests as you and it will be easier to make friends.
Next time you have to talk about work assigned ask someone how their weekend was or something. That doesn't mean you have to start a big conversation but shows other people that you are open to conversation. You won't make instant friends but its a start.
You're not alone in feeling this way, and I know you can do it.