How can i harness my anger into positive energy?!

I live in a small 950 square foot house with my parents and sister. I have 2 baby cousins who are crazy loud that live in the basement with their parents. These kids have the tendency to be loud all the time, so I end up losing hours of sleep. The careless antics of their parents also means all my cd's and dvd's get scratched all the time, and i have to redo projects they manage to destroy (their parents dotn even listen to me when i tell them not to let them come into my room since my lock doesn't work). Also, i have some cousins who think it is okay to come over all the time (3 + times a week) and stay for 5 hours meaning: A) I have no alone time B) Am not allowed to have my friends over whenever i want C) have to wait hours for food, since my parents don't believe in cooking food while family is over. This means i have dinner at around 10 pm all the time. It wouldn't be so bad, if my dad wasn't such a cheapskate. He doesn't believe in buying anything he doesn't like, even if it comes to food. Ex. i asked him to buy me some ham or something, so i can at least have a sandwich while my family overstays their welcome. His response, "No", so i am stuck waiting until 10 pm to eat. To make matters worse, i am skinny. I've been trying to put on weight for so long so i can be healthy again, but at the rate of starving myself from 4pm - 10 pm daily, it doesn't seem like it's going to work. I also try asking my parents to buy me weights so i can atleast get fit and try out for the soccer team like i sued to, but they just say "Oh, as soon as your aunt moves out of the basement". They've been saying that for 5 years now, and i leave my house to live on residence for uni in 1 year -.-.. They never support me, are cheap, and even shun me when i made a robot that was able to interact with people and do some pretty amazing things "You wasted $50 to buy a motherboard for that?". Living here, my creativity is shunned. I am shunned. My 4.0 gpa is shunned. By living with these awful people, i've just had anger building up inside of me for the past 17 years. I don't want to turn into an angry person, and say things that will hurt their feelings, but it's guaranteed to happen at this rate. Is there anyway i can harness my anger into positive energy? Or at least kind of suppress it before i move away from this house forever in a year. Thanks for your answers in advance