Hi! I am not a doctor, but I am pretty positive that your weight gain wouldn't be due to chewing ice. Water doesn't have any calories, fat, carbohydrates, protein, sugar, etc... It is true that you can have a few extra pounds of "water weight" due to water retention, but--- if you are progressively gaining weight, the most likely cause is that you are consuming more calories each day than you are using up each day. I have heard many people say, "I hardly eat anything", or "I really don't eat much at all". However, if you are "really and truly" being honest with yourself, and you "really and truly" want to lose weight, than you will need to acknowledge that you are in fact eating more than you are admitting to eating. The best way to gauge how many calories you are consuming, is to write down even the littlest morsel of food that you put in to your mouth. You might be very surprised at how much you are actually consuming each day.
I hope that you find the root cause of your health issues and I hope that you feel better soon. I know from personal experience that eating healthy and exercising is so important to "well being". It changes the way I feel about myself, and makes me want to feel even better.
Best wishes to you! Keep us posted!