You listed the reasons you may not be losing weight, so focus on those. Get more activity. Drink more water. Eat more protein. I eat 1200 calories a day, so I don't necessarily agree with Grady on the 600-800 calories a day, but I also don't remember how much I ate at 6 months post op, so maybe that's about right. But, regardless, focus on getting your protein, water, and activity up. At over 1 year post-op, I still supplement with a protein shake or Quest protein chips every day; if I didn't, I wouldn't get enough.