Joe,
I was in exactly the same position as you about a year back. I went around all the local airfields scouting out odd jobs for free flying, and even asked to tow gliders (unsurprisingly they wanted more experience!); you don't ask, you don't get :-P
Eventually I stumbled across a fantastic value for money syndicate. Not advertised anywhere, but just came up in conversation. So happened I talked to the right person at the right time, and we exchanged certificates. So now, I'm flying a Cherokee for £35/hour dry, with a £30 monthly fee.
I'm working for every minute I fly, but I'd rather spend the money on flying than alcohol and any other expensive teenage whims!
I'm not sure to what extent you have been asking around, but throughout this thread there is strong advice to speak to whoever you can. I strongly advise you to do so, and you'll be pleasantly surprised how many people are willing to offer you advice and opportunities, in exchange for simple manners and as Pilot DAR says, charm.
Dead Side.