Young lady, your brother has very severe impulse-control problems on top of anger-management problems, and that is a highly dangerous combination. Attacking you shows that he has no respect for you. Those are the three ingredients for rape.
You need to immediately get away from him and sever any contact, then tell your parents. Tell them everything. Refuse to be alone or even around your brother. Do not, under any circumstance, allow him to be within a hundred feet of you. If he gets angry enough to attack you, he will get angry enough to try and exact revenge for revealing his abuse.
You can try sitting down with your parents and your brother to talk this out, your brother could very well be having his own problems that he needs help with. People don't just randomly get angry and attack other people sexually. There is usually a LOT of pent-up and unresolved problems behind it. So, if you feel you can safely arrange a family sit-down, try to get your parents to get your brother to open up about why he's been doing what he's been doing, but I have to reiterate; as long as you live, never again allow yourself to be alone with your brother. He has proven himself to be unpredictable and violent, so there is no telling how far he will go. Do not trust him. Make sure you tell your friends that you are never to be alone with your brother under any circumstances.
Get away. Get safe. Don't listen to anyone who doesn't believe you, and don't let anyone talk, bully, or shame you out of revealing your brother's abuse. You have the right to see to your own safety. If you need to discuss this further, my inbox is always open.
This website contains vital information for identifying, surviving, and ultimately escaping abusive relationships: www.newhopeforwomen.org