Family problems... any advice?

ok so i only get along with my mom my dad yells at me everyday and well my brother and i just never get along really. i try my best to be good but my bro just hates me and my dad is like so bipolar at one moment hes yelling his head off at me and the other moment hes smiling. my mom smokes and im scared she'll die. money is tight right now. im trying to deal with school friends and stressing crazily bad. also, i feel my parents might have a divorce. anyone have advice for me to like relax or anything???