If you think having a fresh start would be the best thing to keep you on track, go for it.
Ok maybe you won't get the awards if you don't have as much to lose now as you did when you started, but you know what you've lost from when you first started. You know exactly how far you've come since you made that first decision to walk into a group to lose that weight to make yourself happier.
For me, that's the most important thing. You know what you've achieved so far, and as long as you know it, that's the main thing.
Good luck with getting back to target, whatever decision you make