I think it all depends on what Primary Care Trust you're in to be honest, because it varies hugely. Each PCT has a criteria set out for any kind of cosmetic surgery, so you need to give them a call and ask them about what theirs is. I know someone who had a gastric band, lost 9 stone and then had a tummy tuck, on the NHS, but then as Emma said, some places may not give you any cosmetic surgery after an NHS funded gastric band or bypass, so maybe the fact that you're doing it alone will benefit you.
Though to be honest, getting cosmetic surgery on the NHS isn't easy, you have to jump through a lot of hoops! Normally it starts with your GP and they'll refer you and you'll then see a plastic surgeon for a consultation. But then you've got to go and be assessed by either a psychiatrist or psychologist and they look at whether there's enough psychological or physical benefit from the surgery. I think they look at social benefit too, though to be honest I've got no idea what that includes!
So basically, in short, it's possible, but difficult, and the only way of knowing your chances is by having a chat with your doctor. You can still talk to them about it now, see what your PCT policy is, ask about when you'd be able to be assessed and put forward, what the criteria is etc.
Hopefully you won't need it and being young will go in your favour!
