I am so stressed EXTREAMLY!!! need a room with no sound and bothering!?

i dont know where to begin. i am 15 with an older sister and 2 parents. ok so i live in a medium sized apartment where we own the house and created it into a two family house...we got the upstairs they, and our neighbors have the down stairs.. the problem is, is the house my mom is a PACK RACK HUGE.. the dinner table is alway full of junk where we cant even eat... the whole house is full of junk that i dont even have a closet. the closets are used for junk. my house has 1 small bathroom, 3 bedrooms 1 big bedroom 1 medium sized and one 6 by 7 bedroom extremely small with no closet! we have a medium sized living room small kitchen small dining room and a play room that is large in length but no more than 6 feet wide in width. the problem is is that there are only 2 doors 1 for the bathroom and 1 for one bedroom. there are no hallways so basically there are just big door entries to every room... the problem is, is that i have a very loud house, where i love to live quiet for homework.. my sister has been very crazy since she was young she likes to fight every minute with my family and i mean scream, and fight, and when she is not fighting she is in the play room on the computer talking with friends and blasting music. my dad is always on the t.v, which is right next to the dining room. my dad made me a desk in the playroom where i can do work but i cant because of the loud house... the loudness comes from... Fighting computer talking, everyday relatives or my sister's friends come over.. I CANT STUDY!!!!!! i dont even have a place to sit down and do my hw because the desk turned out to be a pack rack place for my mom... my parents room is huge but full of pack rack stuff so you cant even get in the room.. my sisters room is meduim and buitiful,, and not noisy at all when you close the door in her room.. but my sis refuses to let me use it when she goes off to college next year. My room is so small it barely fits my twin size bed and when you walk into the room you have a half a step and then the bed is right at your feet.. the other problem is that my bedroom and my parents bedroom dont have heat or air condotion and it is nearly impossible to bring it to our rooms. another problem i have is my parents... my parents have almost every other day.. making it impossible for me to sleep, and im scarred from it!!!!!..i am trying to push for my bedroom to be in the playroom but they refuse what do it DOOO i want quiet!!!!!! i love quiet i cant stand the yelling the talking the, the music the everything its impossible!!!!!!!!!!!!!!!!!!!