If you really do not want to be in the relationship, like you said at the start of your post, then you must end it. You know, it's so hard to end a relationship, and also be dumped, but its something we all go through. If you are being abusive towards a g/f who already has her own issues, then you will more than likely be making her worse too. But there is no point, no matter how difficult, in staying with someone for the sake of it, or because they cannot deal with being single. You need to do yourself a favour, and also her, she should be free to find someone who loves and treats her with respect.

I agree, it takes a lot of courage to see your own faults, and its a step in the right direction with trying to fix yourself, if you so wish to. I very much recommend seeing a therapist too. I also recommend perhaps trying to help yourself while being single, work on yourself, find yourself some peace and start to like yourself, and gain some confidence. I do not think its fair to be like this while with another person, sorry to be so blunt, but there is no excuse or reason good enough for violence and you need to sort that out before embarking on a relationship. Were you like this with your last g/f or is it a new development?

Anyway, therapy if it works will give you more peace with yourself, more confidence and an understanding of your triggers. You may just be able to have a more fulfilling relationship with your next g/f and both be truly happy.