Ereiam

I had bypass on 5/16. Three days before the surgery I weighed 270. The day of the surgery I weighed 262. Now I weigh 246. I got down to 250 in the first two weeks but have since, 2 weeks later, only lost 4 pounds. I'm eating around 800 calories a day and my carbs are under 50. I walk about 40 minutes 5 days a week. My nutritionist told me I should lose 26 pounds in the first month. I've lost 24 since the three day liquid diet, but only 16 since surgery. I am frustrated. I hear and read about these people losing 4-6 pounds a week. Not me! Am I doing something wrong? Too many or too few calories?