Deeply hurt girl

We should enjoy in life-they say,we should be happy-they say, so have fun and don't waste your time on facebook and things like that-my mum says.
But how can I enjoy in life, how can I be happy when I don't deserve happiness. When I don't deserve friends and boyfriends and life. That's not my opinion, that's opinon of strangers, of people who think they know me but they don't. And I know what do you think now-what do you care? Well I care because I care about people who I hate and I care about people who I love and I care about people who I don't know and I care about everyone except myself. And I hate that, people usually think well that's great, you are a really nice person, but no, I'm not, I'm a terrible person. Imagine to hate someone and then one day you get something that that person wanted whole life and then you feel sucs, you feel like a rat. And then it's get worse, you can't look to that person because you are sad that she didn't get what she wanted.