My brother never needed help in school but I do?

My brother is 2 years older than me and all his life he never needed help with school. Our parents are always working so we can not go to them for help, we only have each other. He always tells me how I'm stupid and dumb. Today he told me "You can't do it, you can't even solve a simple math equation. I've never needed help all my life, there's a reason why I think you're stupid. You need my help for simple math problems." And I told him in return, "they put me in the highest of math classes for the last 4 grades, i haven't struggled till I hit 8th grade and they put me in algebra. I do need help and I'm not afraid of asking for it." Then I left, I broke down in tears because honestly, he tells me everyday that I am stupid and I believe it secretly. He's been telling me the same thing since I was 5 years old. Now I wonder, how does my brother go on with out any help?