I am in emotional pain

Today I was hanging out with my Grandma and one of my brothers said " come on you sissy. You are so slow." My brothers left and my grandma was saying how it would be a disappointment if my second brother turned out gay.( I have recently discovered I am bi.) It hurt so much. Like a stab to the heart. I want to tell my family, but I am not ready. It kills me everyday when I can't tell them. When I am alone I go into my room listen to "Same love" and cry. Please help. I don't know what to do.