Thank you first off to everyone who replied. You all gave me something to think about and depending on the reply I may well have found what I want to do.
I was looking through the jobs section of a UK magazine Horse and Hound when I came across an ad for a centre that specializes in retraining OTTBs. From there I wandered over to careersinracing.com. I have looked at racing before. I had planned to do something about it when I turned 16 but quite a lot of rubbish fell into my lap before and around that time so I didn't and went to college instead to do A-Levels as I couldn't face moving away at that time. Well I was looking around again and I have applied for the Foundation Apprenticeship at the British Racing School for when college finishes in July. It suits me well because with being small keeping my weight down is easier because the right weight for my height is lower than someone who is taller. It also makes things easier at home because my mum actually likes this idea as once the residential part of the course is done the BRS finds a yard for you to finish off the rest of the Apprenticeship and it is only the place you are certain to get a job after graduating or you can go onto the Level 3 Apprenticeship. It's the only horse career she likes apart from Mounted Gunner in the British Army which I can't do because I'm under height by quite a bit.
Now all I can do is wait and keep reading the racing sections.