Iv giving up my sweets and have drank nothing but water for weeks! so why am i gaining the weight instead of losing it?

Eating other cals: Mathematically speaking, you must have increased calories somewhere. As if you eat less calories and increase exercise to burn off more than you take in, you will lose weight. Take a diary reading of your daily meals and follow-up with a nutritionist to help formulate an improved meal plan to help you lose. Best wishes.

Depends on what: Else you are eating and how much, and how much exercise you do. Discuss with doctor and have your thyroid checked.

OBESITY: Lossing calories goes together with exercise to get rid of stored fat. Good luck !