Why do I suck at life?

[_digital_dream_]

So once again I've been an immense success at alienating/pissing off almost everyone I know...I don't know what the hell to do anymore and I'm absolutely fed up with being the nice guy that everyone walks all over. I just want to fit in without having to stress myself out by doing about 50 billion things at once. I'm an emotional wreck this summer, and I haven't felt this way since high school...the fact that I care so much about the people I am friends makes me feel like absolute shit whenever they get pissed off at me. Why is it that I'm such a great guy when I can do things for people, and take the shit they dish out to me...but as soon as the tables are turned I'm a complete asshole? I go out of my way to make things work, and as soon as I get fed up and need a little help I become a selfish asshole...I really don't get people at all anymore. I'm either a saving grace, or the Devil's Advocate...can I just be me for a change?
I'm starting to hit rock bottom the way I did senior year of high school and I really dont want to go through that all again...this time I may actually need to go get help.
I'm sorry for anything I've done to upset anyone lately. I just don't know what to do with myself anymore...and I don't think I've ever felt quite this alone....
please don't get me wrong, I'm not crying out for sympathy or pity...I just need a place to vent because I'm not very confrontational...probably why I get taken advantage of so much...
p.s. - I could use my best friend back...