Time for a little Q&A.
Q: So, the family's not home (most of it, at least) and you're looking for something to do by asking us what to do?
A: You've already found something to do, albeit temporarily. Find something that interests you, even if someone else objects. What can they do? If they punish you for doing something that they don't like, then that means they are more concerned with who they want you to be than who you really are, and they should be ignored. Freedom comes with the price of security, and security comes with the price of freedom.
Q: You say you have issues with the with your family, especially with (1) your old-fashioned parents and (2) your most-likely homosexual drug-dealing little brother?
A: (1) Draw the line somewhere soon. It doesn't matter where exactly, that's for you to choose, but there is a limit to how much your parents expect you to do simply because you are their child. (2) Get him to own up to everything he is and will be. You say that he is trying his best to become a responsible person, and that is good. However, if he cannot be honest with himself and others, there will be major problems in the future. Your role as older sister is to support and guide him, even against his will. Do not force his hand, and let him decide what it is he wants to do, but NEVER hate or disown him. Accept him and forgive him, if necessary.
Q: In addition to your family problems, you have issues with yourself and the way you look?
A: Do something about yourself, or get used to your life. If you want to change any part of you, you must ask questions and answer them in kind. Who are you now, and who do you want to be? What is it that you want? What do you think you will gain or lose by doing this? These must be answered truthfully because there is no point in lying to yourself. After you have done so, decide. Will you go through with it? Will you change and risk losing a part of who you are, or will you remain the same and risk regretting your decision?
Make your time.