Melody I had RNY. I havn't lost nearly as much as you but a couple questions come to mind.
Do you get enough protein in? How many grams per day?
Do you take your required vitamins (B12, Multivitamin, Calcium Citrate)?
800 calories sounds like its not enough, you should probably get at least 1000 calories a day.
Lastly, do you do any resistance training? I hired a personal training because I have lost nearly 40 pounds in about one and half months. So I am trying to fight the sagging. Going to the gym is a must and building muscle is a must must. It really helps to burn fat but builds that muscle that has been tucked away for so long.
I hope this helps
Congratulations on your weight lost and discipline. I think you are doing great