Waves,
I am also so sorry about your friend. Even though she had cancer and it might have been expected it is just as hard! You are really going through a hard time and for this I am also sorry. Sorry, that seems to be all I can say to you! If you cannot vent to your parents do you have any friends you can talk to? I don't so I usually end up talking or venting to my therapist. Is that an option?

collinsc