I see no mention in your post of whether she's happier now, or whether you believe you're capable of making her happy. I think that's indicative of your relationship problem: you're focused only on yourself, even after a supposed epiphany about how selfish you are.

Also, why are you posting this here? It has nothing to do with hacking. If you don't have any close friends that you could say these same things to, you should see a counselor. There's no shame in it -- we all need help sometimes.

Excessive drinking is only going to result in feeling worse and, most likely, more alienation.