I'm particularly impressed by your weight loss during your second year! I'm not familiar with the Loop DS procedure, but in my case (gastric bypass), it became very difficult to lose weight after the first year and I had to start watching my food intake pretty carefully--so you are clearly doing something right.
I had a 20-pound regain fairly quickly in maintenance (the beginning of the second year). However, I actually lost too much during the first year and needed to gain about 15 pounds so I didn't look so skeletal. (Sorry.)
I have found maintenance pretty easy by sticking basically to a high-protein, low-carb, low-fat diet. If you are getting 100 grams of protein a day, that's great! You can definitely eat more that 1300 calories without gaining weight. However, it really can be terrifying after eating so little for so long.
As someone mentioned, it really is trial and error. I'm able to eat some sugar, have an occasional glass of wine and high-carb treat without too much trouble. You are clearly very disciplined, and you know your own body better than anyone. You'll figure it out. Good luck!