Acting and dancing

I am turning 15 in May, I desperately want to become an actress, my inspriation is Catherine Zeta-Jones. I have done some small acting when I was younger, but not much after that. I am a dancer and have been since I was two, although I unfortunately dropped out of the academy when I was 10. I have no support what so ever from my parents or family, for that matter in persuing an acting career. I don't mind where I start out, but I want to be able to prove myself to them -- or even to myself, that I can do anything I set my mind to. I've tried to find an agent in Brisbane, but there isn't really that many. Can you please help me, what do I need to do, I need to give myself some worth, because I know I deserve more than I'm getting from my family. Thank you.