I too am in my 20s and have already lost WAY too much due to my alcoholism. I can definitely relate to drinking to relieve stress, fears, etc... pretty much any emotion. But we alcoholics can rationalize anything, ya know? It sounds like you have a girlfriend that cares about you a lot - that's wondeful.
AA is not for everyone, I understand that. I just recently started going about 3 weeks ago and it is the reason I am sober today. That, and my sponsor. Before writing it off, I would consider attending one meeting. While there is a great deal of mentioning the "higher power", your higher power can be anything - karma, a rock, the sun... seriously, anything. Also, you can just sit in a meeting and not say anything. There is never any pressure to share. Maybe you could give a counselor if you are still unsure about AA?
The thing is, we don't have to live this way. We don't ever have to pick up a drink again. I wish you the best and hope you continue coming back.