Hi Rich,
Becoming sober is a very scary thing. I spent three years drinking and running away from all the emotions in my life. When I stopped I had a lot to look at. And, some of it was not at all what I expected.
It sounds like you need to find a good way to deal with your anger. I found that exercising helps and knowing when I need to spend time alone with myself. You really need to figure out what works for you. Unlike you, I directed most of my anger inwards and did not feel good about myself at all. But, I found ways to begin to change that.
It sounds like you can talk to your g/f so let her know you need to deal with your emotions in healthy ways. As far as being unhappy and alone while she's away. You know that's a choice you can make. You can also choose to enjoy your time by yourself and do things you wouldn't do if she was there.
Hang in there Rich. It sounds like you're doing great.
Love, Anna