Wow... Sounds alot like a person that I know. Its really sad that some women have to lie to look like the victim or the good guy.
Personally, I would wait until you are 18 and try to get guardian status of your little brother and get him out of that house. Maybe she was just having a bad day or something. Sometimes fighting back isnt the best solution for this form of "discipline". If you can't stand looking at her, its best to let her do what she does and then call the police, it might sound redundant and useless, but it will help.
As for me, I've never had any family problems, I never had a chance to meet my dad for real and my mom died 4 years ago.
Good luck with your problem, you sound like a great person.