I feel like I should cut off my toxic brother.
Oh my gosh are you serious about this? Why do you want to cut off your brother? He sounds horrible already.
He always sides with my parents and never with me.
I mean, if he's really toxic, you should cut him off. However, you shouldn't just cut him off because he disagrees with you. You should try to see his reasons for what he thinks.
I have better family members and I don't have time to waste arguing with him.
I have a toxic brother too and maybe it is just that you have different personalities. Try to just avoid arguing and speak in normal tones as far as talking. I know sometimes it might be difficult but the sooner this is done the better it will be later on in life.