I basically don't have any friends either. Never go to parties or anything like that. It sucks. I mean, I have lifelong friends that I stay in touch with (call once every 6 months to say "hi" or message on myspace) but I've basically made ZERO new friends in college. I have a boyfriend and a daughter who suck up a lot of my time too, though. It's great to have a boyfriend, but as a girl, I want to have girl friends too, and I just don't have the time. I started trying to make a bigger effort this past semester, but I didn't really succeed. It takes time and energy, which I don't have any extra of.
My friends are my books. This is true for premed, and it's true for other readings (theology, politics and Harry Potter, mostly). I guess I'm a bookworm. Oh well.
Another thing that I've done to feel as if though I've got some sort of support system is get extra close to my extended family. Grandmother, aunts, uncles, cousins, second cousins. I contact them all on holidays, birthdays and on weekends when I have time. I visit them as often as I can (I live in 35 miles from my 17 year old cousin). Family is always their for you, and you don't have to make so much of an effort to befriend them. If this is an option for you, I recommend it. Cousins rock! (I have no siblings).
Try to get out into the sunlight...it helps. Open the windows to your room or something. I had been depressed lately, and going to the swimming pool really helped. You see the beauty of nature, enjoy the sun on your skin, the water is sooo refreshing! It reminds you life is good.
Try to find at least ONE person who can be your best friend...instead of a "group" of friends, which is much harder. You need someone to talk to, you don't need a group, nor do you need parties, even though those things are fun.
I hope this advice helps.