I had an operation a few months back and since then I've been losing a lot of weight. I've calculated by BMI and apparently, I'm underweight, almost severely. I know people will say "just eat more" but it really isn't that simple. It's problematic for my stomach to adjust to larger portions. My antibiotics are also causing extreme fatigue; I can't exercise regularly like I used to (exercise really helped) and I sometimes skip meals. All this is making me so depressed and my mood really affects my eating behavior.