Is it normal that i want to leave my family?

I want to leave my mother and younger twin brother. Why? Because they always argue along with saying things behind each other's back like immature school children and it tears me apart both emotionally and pychologically. When I get upset by it, I have to turn to my dog for comfort because I have no one else to turn to. Once my mother doesn't need me finacially anymore, I'm leaving. I'll be moving to Wyoming and they will never see me again. Has this ever happened to any of you as well?