Okay so I know I have mental issues, my moods change so rapidly and sometimes they are very violent. When I get angry I don't remember what happened I get what I call an emotional blackout. Which is when you don't remember what happens when your emotions take over. I have beaten people up and then the next day never had a clue it happened. I have an unstable self image and am very pessimistic. I'm very unapproachable for the most part. I over eat and am unable to keep a boyfriend / friend for more than 2 months. I told my mum about it and she said there is nothing wrong with you your just a normal teenager. Nobody believes me. But I know something is wrong. I need help and an unable to get it. IIN that my mum thinks nothing of it?

I really do hope you get the help you deserve. Take care xx
Also you will release more stress, and also bring health to your life, also helps if overeat.
For the remembering part, hmm it's a blackout or you just don't care too much about the fight, if it's the first one try a medic that could be some chemical unbalance in your brain or worse, 2nd one no problem.
About the relationships, I think most ppl have problems haveing a stable relationship, that comes with time.
Obviously something's happening with you and you should ask for help. If nobody helps you, try to make it seem worse than it is. Maybe if they're scared of the things you do, they will take you to the doctor.