I need help!

Okay so honestly I know this is really stupid but it has really got me confused. So I just turned 17 and I was listening to music like always until I heard a quote from Tracy Chapmen Fast Car, the quote was, "Leave tonight or live and die this way" this quote really got me asking myself questions. Im in Sixth-form taking Art/Graphics and Financial Studies, I have always had a passion for Art and photography but my grand parents have over the years forced upon me to go down the architecture root or a financial adviser which until now I always accepted. I am half way through my first year in sixth form but I am not happy there, not at all. I have been in the same school with the same people for 5 years now and I need a change. I need a new chapter in my life. I want to start again in college and take a BTEC in Art-Photography-Photography media which really really interests me and I think I can achieve a very good grade doing it, it would be something I love. The BTEC gives overall 4 A-level equivalents and the college helps you get employed or into university.
Honestly, I do not know what to do!I have got myself all worked up and im really struggling at the moment anyway. I have always struggled to talk to people and have suffered with Anxiety and Depression which both effect my epilepsy as my epilepsy is triggered through stress and so on. Like I said previously I take art and I am so passionate about it however, my teacher has really destroyed art for me. I get nervous before going to each lesson because he bullies me. I showed him a piece of work once and he laughed, said "that looks as if a homeless person drew it, I really want to rip it up and throw up on it" I then got the highest possible mark for that piece of work from the examiner. The problem with this man is that he is the head of Art and friends with all the higher up teachers.
Anyway this teacher is only a very small fraction of why I want to leave. Graphics is the other subject that I take which I am getting such terrible grades in because I have no motivation for it. In fact I have no motivation for education at the moment. I wake up every morning in tears, crying to myself in the shower saying "I dont wanna go" or "I cant do this again everyday". I have always loved school because of my friends, my mum has said to me that I need to start being selfish about my life and do something about my education for my own sake. Ohh yeah another problem is that I literally never talk to my parents about anything school wise, I have always been uncomfortable talking to them about these things. I dont have anybody to talk to this about and I have always felt as if I am alone in this world. I know this is probably the wrong website to post this on but Yahoo wouldnt let me post it as apparently its to big? Anyway any help or advice would be much much appreciated! Thank you everyone :smile: