im scared of my brother?

my brother has always been abusive to me whenever i called him a name.
im not talking a little shove, he would kick me and puunch me,
today i was on the computer and he came in and started playing piano , i started singing out loud cause i know it annoys him. after that i went into the kitchen and started making soup.
he randomly started charging at me and grabbed me by my neck kicked my arm when i fell and threw me outside
after about 5 hours of being stuck in the back garden my mom finally came home
she didnt believe a word i said! he told her that i was kicking him and pulling his hair and that i punched myself!!
now im in my room and have baracaded the door and im absulotely starving!
its 5 o clock and all ive had so far today was a bowl of cereal at 9 in the morning
im too afraid to walk to the kitchen because he said that hell put me outside again and hell punch me again
my mom doesnt care
im 13 (and a girl and hes a 15 year old boy.)
please help!
i dont have time to talk to a teacher or anything i just need a plan, maybe somehting to trick him or some self defence! thanks x i really need help!
oh and i have really low blood pressure and am feeling dizzy

Girl, i hear you. Trust me i have the same thing with my brother, what you need to do is; Fight back, make him scared of you. Trust me it works. Thats the first over-all thing right. Take something that he loveeees, and threaten to destroy it, take something like a long stick to push  him away if he gets close, make a deal with him, if you get to get some food and water, he'll get his precious thing back. That should work. Also my bro is 3 years older than me, and fighting against him has really helped, seriously you'll be able to take down any guy if you fight your bro Good luck! Girl powah!

But yeah, if it gets way out of hand with him, tell your mom to test him, he might have ADHD, so he'll be prescribed with pills to calm him down. Also, don't second guess calling 911 about anything. Alright, be safe and good luck again!