Break ups are a bitch

[Herr Mullen]

If she isn't willing to forgive me for some stupid mistakes, she's not the girl I want to spend the rest of my life with.

And I do know that I'm not date material. I've flirted with girls before, and they either ridiculed me or didn't get the message. And actually, I have done an identity change. I use to be a loud, outgoing guy. Now I'm a dark loner who avoids attention.

You don't need to spend the rest of your life with her; you just need closure. You still haven't accepted it's over, and that there's absolutely no hope; the fact that you're pining as you are is proof. Get a girl who is friends (or on good terms with) both of you to sit you two down so you can ask each other why you did whatever you did. Once you understand her feelings, you can understand why it's over and that makes everything much easier to accept.

There you go with self confidence again; "I'm not date material, girl's hate me..." You need to build confidence in yourself. And that isn't a good persona change; you need to go out more, not less. Get a constructive hobby.