He keeps saying/doing dirty things

My little brother and me aren’t very close, but he has said weird things about me in the past like.. Your ass jiggles, you look best in the shower, your hot, etc. my parents have made it clear to him that if he ever says something else he will be grounded. Today my parents have been gone and our grandma has been over. He has done/said so many more things!

He said suck my dick.. I was so mad that set me off the edge so I got so mad I was trying to get out the house with any excuse. My grandma didn’t even know why I was so mad so she started criticizing me saying I’m a bully. I told her exactly what she said And she took his side. “Don’t repeat what he said! Your a lady, it’s not classy.”

None of my friends was okay with me coming Over today because last notice.

Then we have a stick in our house and my brother smacked my ass saying move your booty..

And I screamed stop it so loud my grandma yelled at me. Don’t know what to do.