First and foremost: do you REALLY want to change?
That's the problem most people on this board have; they want a better life, but they don't want to take the action necessary.
If you really want to change, you can do it. It's going to be really hard, but you CAN to do it.
Psych yourself up, open your door, and say to your parents: "I need help."
And although it'll take a lot of courage, and it might be embarrassing, you need to make yourself be truthful to whoever you talk to.
If you really want to change you'll be able to be truthful.
Good luck!