Are there any diet plans I could go on to loose 1 stone in two months?

Diet plans. Most effective diet plans are those that involve permanent changes in eating habits. Portion size restriction, calorie restriction, low bad fats (animal, trans), low glycemic index foods (avoid white bread/rice/pasta/potatoes). Combine these with exercise program: walking is the safest exercise—low impact, easy on joints. Commercial plans like jennie craig & weight watchers seem to work well.
Crash diets. Crash diets don't work very well. You need to slow down that food and fat at a rate that decreases you bodies cravings for it. But turn vegan (if it has a face don't eat it, no dairy, no nuts) you'll lose weight fast. It is difficult to do this. Otherwise, you starve.
Stones. Plenty of fluids. Avoid foods high in oxalates or phytates. It all depends on the type of stones you have.
Crash diets. Vegan diets, lose alot of weight quickly. They are hard to adhere too, especially if you travel or eat out. If it has a face or a mother--don't eat it. No nuts or dairy either. There is your most difficult wt loss, besides keeping your mouth shut.