Could this be low self-esteem?

Ok, there's a lot I need to say. To start with, I'm a 19 year old female, in college, very bored with my life and tired of monotony. I guess that's to be expected of anyone my age, since I feel like I've really only just begun to find myself.

Recently, though, I've noticed something that's bothering me. It's been going on for about a year, but it's only just now becoming something I can't stop thinking of.

I feel like I'm in some kind of limbo. Nothing about my life is changing, I'm staying in one place. Since graduating from high school last year, I've grown distant from my friends, most of whom are seniors this year. I never really felt that close to most of them, we were friends, but not good friends, which was ok back then. Now, I find myself desperate for real friends, yet I don't feel like I'm able to get close enough to anyone. It's hardest for me to get close to guys, maybe since my dad died when I was 12.

I know that you just need to get out there and go for it when you want to make friends, but what will I talk to people about? I don't even know what I'm interested in, and the things I do like aren't very widely accepted. I'm changing a lot, and even I don't know if it's good. I cut my hair, dyed it, lost weight, started dressing differently (not drastically), even went out and got a tattoo, which I love, btw.

I need to have at least a few good friends, right now I only have one real friend, but I can feel myself growing distant from her, too. I'm worried that people won't share anything in common with me, or that they won't want to be my friend. I have this stupid, irrational fear of imposing myself on others. I never go to hang out with anyone, I never invite anyone out, since I don't know anyone well. I'm too afraid to get close to people, and I feel awkward in social situations, as if I was imposing myself. I never had felt that way in the past up until about a year ago.

I don't know what's going on, but I'm tired of it. Sorry to have written so much. But any help would be appreciated.