Damon was never “bad”… Damon’s always cared, and has always been blind for love.. just look at the flashbacks. he died for Katherine, because he thought he loved her. His problem is that he’s suffered too much, that he rather turn his feelings off, because there’s so much hurt a man can take.

And now, even when he said to her in episode 3x04, to make her stop trying to change him, he didnt really mean it, because he does want to “change” for her, he HAS changed for her (when I say “change” I mean, stop hiding his feelings, stop pretending like he doesnt care, stop actiong like anything matter, because he knows that it’s not true, and so does Elena) and he’ll do anything he can to be the man capable of deserving her love… and it’s not about being the man Elena wants, it’s about being THE BEST for her, because he loves so much that he just can’t see her with someone that isn’t as good as she is. that’s why he let her go. he thought he would never be this person.
And also, yeah, sometimes Elena pisses me off, but it’s not that she wants to change him, she just want him to be himself. she just want him to stop pretending he’s bad and that he doesnt care, because Elena knows better than anyone else how much he cares. and seeing Caroline and Bonnie talking crap about Damon “hurt” her, because she wants people to see him the way she sees him. she wants people to see how much he cares and what kind of person he is!

And Damon and Katherine.. just can’t be anymore. she lied to him so many times, and yea, she cares about him, but no, she doesnt love him. and Damon is over Katherine. it took him 145 years to realize what kinda of person she is, and I really dont think he’ll ever turn back. he fought for her, he waited for her, he did everything he could, he didnt give up, so now, when he’s moved on he can be sure that he’ll never regret leaving her, because he knows it was not his fault that they didnt work out.
And I’m sorry about the spam LOL