Me and my brother don't gel atall

In my family it's my mother, 1 elder sister (married) and 1 elder brother (divorced). My father passed away when I was 8 years old. nnMy extreme big Problem is my brother, he drinks too much and even has a bp issue due to drinking and has immature thinking. I cry out that we all should have unity among our family but even my mother fails to understand and she supports him because she gets money from him as he's doing a good travel job. But isn't strict in anything ever. I am highly agitated. As an example what irritates me the most is 0 understanding in family not just towards me but how should one family be if confident and strongly together. One scenario if I tell you is in a get together like our cousins and all come to meet us at home and all being loud and talking and out of nowhere if I am talking, my brother would start waving hands to stop me for talking showing that he can tolerate all others being loud but not just me. It's been happening for years and I have no more to take