My life is good, but I feel bad

I have family, and friends, and my grades are good, no one's bullying me or anything... But I still kinda feel bad, you know? As if it could be better, or I could do better...

I always try to do my best - help people, be kind, be smart, not be a burden, be fun to be around, etc. But sometimes I feel like people don't think that good of me. I mean, they always come to me just to ask for an answer or borrow something, not get to know me or ask me about my day. And now that I finally have friends... I don't even know what to do. When they ask me to hang out with them... I'm afraid, I'm confused, I don't know how to act. Now, I feel like they don't enjoy my company as much anymore. They talk to me more rarely. I feel like I'm ruining things again.

I'm probably this way because I've had some not very successful friendships before, but if to compare what they did to other people's experience... I feel like my situation is just nothing. Like, yeah, they did kinda betray me and use me for homework, but I wasn't bullied or anything.

Just... I feel like I could better. And less weak. And less sensitive. And just... Normal?

(I know I'm really bad at expressing my feelings with words and explaining, but isn't it what this site is for?)