You are only really a few stone over weight. I was 13 stone over weight when I under went surgery. I like you am only young, (im 21) I would definately try other routes first, go and see your doctor and discuss it with him/her and they may be able to help. Diets such as Lipotrim, Cambridge, Lighter Life and Atkins are also worth considering. However you need to make life long changes, it sounds simple but try raising the protein amount you eat, e.g chicken, fish, eggs, cheese, yoghurt and milk and lower the simple carbs e.g pasta, rice, potatoes, crisps and sweets as if the simple carbs arent burnt off they store as fats, hence weight gain.
Definately think about your options before considering surgery as it should definately be used as a last resort.