How do you go about ridding yourself of a cynical, negative mentality? Please, help?

I think that YOU need to take control of YOUR life. That seems like the main problem to me here. YOU aren't living YOUR life, you're living by your parents decisions. I think that you need to become proactive and step up. Experience is the essence of knowledge, afterall. Make your own decisions, live your own life. Like my dad tells me, "High school is all about discovering who you are... Less so about grades, achievements, etc.". And to me it sounds like you've missed out on your inward journey in discovering yourself. Do things you find interesting, reGARDLESS of what your parents think. Nothing's EVER too late.