Naomi as others have said, you need to seek professional assistance for this situation. The internet is not the place to obtain the sort of assistance you need.
As others have stated, please call LifeLine if you are too scared to see someone face to face otherwise please see your GP as the first point of call.
The situation you have described is not a healthy relationship for you and your brother ... you owe it to yourself and your brother to seek professional help. Please see someone in real life.
The Moderating Team