I'm about to have a mental breakdown?

I'm a junior in college and right now I am in my room and I am about to go crazy. I can't find a job to save my life no matter what I do, I'm tired of depending on my parents, I have absolutely no friends, and my roommate is never here. I'm a dorm rat (I stay in my room all the time), I think I have depression and everyday it gets worse. I used to have a couple of days where I would be okay, and then a day where I would be depressed. Now I battle with depression everyday. I try hard to divert my attention but it keeps coming back. I don't want to go to a doctor so they can tell me what I already know and prescribe me medicine that will only make it worse. I also don't want people to think I am crazy, but I'm about to lose my mind! I keep thinking what's the point of living if you can't live happily? I need some type of advice. Noone should live in this condition...