Everything seems about right! Have you reached out to your NUT and surgeon? I'd say this is pretty slow loss considering what you are eating. One thing I can say, I stalled after 2 weeks post op, and did not start loosing until I started exercising. I mean, cardio with keeping my heart rate increased for 30mins+ per day. This isn't meant to sound bad, but obviously your physical activity at your job wasn't enough pre surgery, so it may not be enough post surgery. Some vets on here don't believe as much in exercise, but we have almost identical stats and exercise worked for me. I'm 8 weeks post op and down 65lbs.
Also, I increased my calories at about 6 weeks post op to around 800-900 calories per day. I track 100% of my food & exercise on MyFitnessPal. I keep my carbs to under 50 grams per day and my protein at around 75 grams. I don't eat any pasta, white bread, processed sugar, processed foods (for the most part, about 95 fresh/5 processed split), caloric drinks, or alcohol.
I'd like to see what your stats are after logging you food for one week.