successful way to lose weight

At  age 40, I was actively involved in sports squash, tennis and golf, although the last of the two was not as heavy as squash . In my early 50's, my weight around 84 kg, was diagnosed with type 2 diabetes, depression, and I was wondering about for my life . After getting advice from a doctor on my diabetes, I started trying to do things in accordance with the doctor's advice and conduct activities to lose weight. I eat food for dieting and thin body, or if I want to, eat crackers and salad.

I tried to hold back hungry, eat only protein, all done more than usual, and lost a bit of food. then Christmas came and my weight back up and I feel depressed again . After trying all sorts of diets, I would always fail. I then read some books how people start a diet, and how many people fail to lose weight, or gain weight after the diet ends. I had to reduce my calorie intake or burn more calories through work or training.

a complete source of information where there is more than 1400 pages of information. There is also a lot of diet information there. I'm into a lot of information, especially since I started to lose more weight. I found the information that how to cut saturated fat, and reduce the desserts, and I continue to eat small meals to lose weight. I do not drink beer, and do not drink wine. In essence, I continue to enjoy all the food before I can enjoy, but with the motto, everything in moderation.
the reality of all this is that with serious diabetes or obesity, you can lie all day and night in the cemetery as if I could not face my weight issues.
While I know diabetes can not be cured, I believe that it can be controlled by controlling my weight, and in particular, my fat percentage.
I am also sure that the information is something that is needed and I can never have too much information. Obesity is a health hazard, so let's beat the disease.