Thanks for posting. Even if your post was a little disjointed - which it wasn't - there would be no reason to apologize. We fellow members of the brain boo boo club understand.
Firstly, I hope someone can help you stop feeling guilty about your brain injury. From emergency room stats, we know that abuse by partners is a leading cause of TBI is women.
That violent individual got the ball rolling. That you went on to self-harm was, as you know, a way for you to cope. The beating-induced damage may well have contributed to your adoption of such a self-defeating coping strategy. In short, I hope you find a therapist who can help you restore the self-esteem your evil partner stole from you. You are NOT to blame for your TBI.
The same goes for the MH issues. Pretty much everybody with TBI has some MH issues, like depression, poor impulse control, anxiety, personality change, etc... Don't let doctors dismiss your problems as psychological. Your MH issues are a PRODUCT of your TBI, not its cause. It's an important distinctions, that many doctors like to ignore.
My suggestion would be to have neuro-psych exam. That would document your brain injury, explain how its impacting your daily functioning and help you target physical/cognitive/psychological therapies that might help you recover/adapt.
Please try and find someone to help you cope emotionally. If you aren't sure where to turn, try calling a women's shelter. There are a lot of compassionate people there, with experience assisting women who find themselves in your circumstances. Sadly, your situation is far from unique.
Remember, you have already survived a great deal of adversity. You've obviously got what it takes to deal effectively with your TBI. Try not to be afraid to let people help you.
Hang in there.