true friends?

It's sad to say that I've come to realize that I have none. No true friends, that are always there for me now matter what, and for the few people that I considered "true friends" for a long time have fallen short. I'm not quite sure how this happened or why I even started be friending certain people in the first place. I feel lost. I'm not sure why I'm not worthy of true friendship. Is it because I'm so much more than people think? Not that I'm better than anyone, but I'm really like a crowd of people in one body, or at least thats hows I feel. My mother once told me that i was too nice. And I'm only now begining to understand what she meant. I bend over backwards for my  "friends" without question; yet none of them are willing to do that same. They only have my back when its convient for them. yet I've put my neck on the line and risked fighting with my family to take care of them. But I see so many people who have friends that would be there for them no matter what, i guess i feel as if i've failed in this part of my life. I mean I've never made a true friend in all of my life, what does that say about me? I realize that i'm the nerd, wall flower, loud mouth, quiet, rocker in one body; but i cant be the only person like this can i? That shouldn't make me less worthy of true friendship than anyone else.I just dont know waht to do anymore, im as real and genuine as i can be and yet it still seems to not be enough. ugh, i wish i had "thick skin" maybe then this wouldn't bother me as much.