If you really want it, then as has been said before, you are in the ideal position to make it happen. You need to sit your parents down and explain to them what you want to do with your life...
Explain to them that the next five years are going to be the hardest of their lives. The drugs. The Alcohol. The gangs. The thieving. The visits from the police and the inevitable arrest and imprisonment... Explain to them that they can make that all go away if they are prepared to support your dream.
Then keep your nose clean. Get A's at school. Clean the car/mow the lawn/do the washing up without being asked. Join the Air Cadets as soon as you can and make sure you solo. Join a Gliding club - they tend to be full of old people who would love a hand rigging/de-rigging, and you might just meet a few airline pilots. You need to aim to Pass your PPL on your 17th birthday. By the time you get there you'll know exactly what your options are and the rest of it will fall into place.