Okay, I'm going through some stressful stuff too. So I think I can say I may understand what pure going through a bit.
First off, focus on the positive things and dwell in the positive. Be overly optimistic when your sad thoughts come about. Don't take so many hours at school while you're going through this!!!
Try to get work study in school. Ask about it in school. Apply for government jobs and stuff. Tell your dad how you feel. Tell him its putting so much stress on you and its affecting you mentally and emotionally.