Trouble with an angry girlfriend

I'm having trouble with my girlfriend. We've been together about 3 1/2 years, I'm 27 and she's 25. We have known each other since high school, we talked/were intimate in high school. She was everything I ever dreamed of, cute, constantly trying to be funny, laughing at me constantly being funny, caring and very generous. When we met in high school I had just broken up with another girl that I was with about four years, I thought that it was over (she left me) and that I was over it. That was until she called one night and said she made a mistake and that we were supposed to be together (I later found out it was a ploy of jealousy over my new found love). I went to her house and we ended up having sex and she left a huge hickey on my neck. By the morning I'd realized that her intentions were negative but it was too late. I told my new love what happened and it crushed her. She ended up not talking to me again and a few months later I got in some legal trouble for drugs and ended up doing two years in prison. About two years after I was released I saw my new love walking down the street in our hometown and we instantly reconnected. I was right back where I left, we talked about how we'd missed and thought about each other, she showed me poetry that she had written four years, all about me and our seemingly lost love. I was in heaven, the so called "puppy love" stage lasted over two years, no exaggeration. I think it's because about two years in her mother died of terminal cancer. Up until that point I'd pretty much been living with her and her mother and helping my love take care of her. She began drinking everyday, for the first summer of our relationship I was laid off and she was on summer vacation from grad school and we went out almost every night. But this was different, she was getting black out drink, angry, and even drinking in the mornings before school. I thought for sure I'd lose her, if not from the anger she displayed then to the alcohol that would surely kill her. She ended up pulling out of the drinking and today has about three months sober (after several less than week long failed attempts). This time her desire to not drink seems very strong. Our relationship was back to that puppy stage, so much love, so perfect. But now she's beginning to find that anger again, without alcohol. She's beginning to say all the terrible things she said drunk but now she's sober. She's telling me that I never do anything for her, she does everything, and that she'd be better without me. As far as I know those things aren't true, unless I have blinders on that I'm unaware of. I don't think I lack care or desire for her and I do everything I can to make her smile, I don't think the "her doing everything" she speaks of is any more than leaving clothes on the dresser instead of putting them away, or forgetting to rinse dishes. Which to me seems like normal male/female differences? She is also saying that I never take her on dates, and that she always takes me. That part is close to true, I take her out a couple times a month but she makes more money than me and takes me out sometimes as much as three or four times a week (taking out: dinner or maybe a movie, date stuff). I try to make that up by doing the cooking every night we're home. I was reading online today about borderline personality disorder and she kind of fits the description but I'm not a doctor and my psychology experience doesn't go behind 101 at a community college so I'm deff not qualified to make that assumption. Can someone help? Is this relationship worth continuing to work on? Any advice will help. Also, I want to say that we don't fight terribly often, once a month maybe and she had always showed remorse afterwards and asked forgiveness. I think maybe me being so forgiving isn't helping, I get over things very quickly and I consider myself really understanding. I have an easy time putting myself in others shoes and understanding what made them do what they did, and also I believe that if I had been raised through the life and situations that they had that I'd have done the same thing at the same moment. Thanks again for any help