Found out tonight that my grandpa has prostate cancer. He is literally my best friend when my grandma called me and told me I was at work and about threw up. I came home and was reasonably upset. When I got home my father who knew, asked me what was wrong. I responded with " I just found out my best friend and grandpa has cancer". He freaked out on me and said "yeah well hes my dad!" He was screaming and tried to get in my face. I told him to fuck off. I ended up going to room and trying to calm down. My mom and him were standing in the hall near my room and I heard him say "did you hear what OP said to me? I'll never forgive him". After that I just ended up getting in my car and taking off. So reddit AITA? 