Why do I care so much?

There are some people who want to see you hurt, sad and all the bad things. You don't have to care about them, but deeply in your heart you know you care. Why? Sometimes those peoples used to be your friends, and now they're just strangers trying to make you feel unhappy. But you don't want them to be unhappy, contrariwise: you want them to be happy. Even if they want to see you dead... You think they deserve to be happy at all. But they don't care about it -- they don't believe on you. It doesn't matter how hard you try to be nice to them, they just don't give a shit.
I'm feeling tired of everything, and now I gave up. I won't look for you 'cause it's really depressing. I wish you all the best in the world and I appreciate all the happines you gave me in years. Thanks for everything, and as I said before... I'm really sorry.