Wracked with self-doubt?

I'm never sure, about anything. I'm the most indecisive person ever, leading me to yahoo answers for a lot of my questions. I'm in college and lately it's been rough. I feel very lonely. I distance myself from my so-called friends, and never seem to get too close to people. My friends all have different groups and I just filter into their groups whenever I want to. I have one best friend, but I don't fit in with her group, and we usually just hang out one one one. I can never find the right clique and it's always been like that. I've been in a co-ed fraternity for a semester already, and still i've only gotten close to one person and made acquaintances with others. Last night we had our Big/Lil reveal and I got a Little but I feel undeserving of her, because I am such a bad leader and will probably never make the initiative to hang out with her and get closer to her. Also, I want to apply to be a R.A. (resident istant), but I feel like since i'm a terrible leader it's something I'd be horrible at and would end up hating. How do I gain confidence in myself and start to grow as a person? I know I need to step outside my comfort zone and become more outgoing, I'm just scared to. I'm self-conscious and feel like nothing I do is ever good enough.