how can i believe in myself when no one else does?

[TheBeast]

I am at a cross roads in my life. I just finished high school and i have no idea what to do. Due to my own personal issues, I messed up school so applying for university or college is out of the question. Everyone around me says without a full high school diploma, i shall forever amount to nothing; no job prospects and that no one will take me seriously, that i will forever be stuck in a dead end job, being a janitor or flipping burgers at Burger King. However, I do believe that i can defy the odds and i believe that with my guitar i will be able to make it in in the world of music. I try hard but everyone sneers at me and says that never in a million years will i be able to build a career and support myself as a musician. I have always dreamed of being one ever since i can remember and i try to believe in myself and i tell myself that with audacity, i can accomplish and amount to something.

However, everyone tells me otherwise and it's really tearing me down. Everyone tells me what i can't do instead of what i can do. I say that impossible is a state of mind, but they say my road is already laid down before me and that i have failed in life.

What can i do to believe in myself when I'm surrounded by negative energy from all angles? It's a tenacious, relentless psychological warfare that's making me give up. Any words of wisdom and advice will be greatly welcome.
wow! Thanks a lot people.How wise and true are your words. Thanks a million!!!

xoxox