What to do about 10 ppl in a 3 bed room home?

Ok so I live in a 3 bedroom home with my mom my 2 brothers(14 and 22) and me(17). My home and one of my brothers(22) have a room while my other brother(14) has a bed in the living room. My mom got remarried and now her new husband and his two kids(boy 7 girl 10) are sharing a room. My oldest brother who is 22 hasn't moved out and is now having his girlfriend move in and share a room with us. That's 8 ppl in a 3 bed room home. And just to top it off my sister(19) who had moved out is moving back in with her bf and new baby. My oldest bro looks like he will b moving out(hopefully) in a month and we r going to add another room but that's still not enough. Idk what to do I can't move out yet I'm still in high school idk what to do. Ideas?