I have been dieting and exercising for 7 weeks?

And not losing any weight!!! I am a weightloss surgery patient. I started at 275 and currently I weigh 180. I am stoked about the weightloss, but getting really frustrated. For the past 7-8 weeks I have been dieting and exercising like crazy. I eat around 1000 calories a day and I exercise about 5 times a week. I get nowhere!!! I have only gained 1 lb of lean muscle m and haven't lost crap. Why would this be? I keep teetering between 180 and 181.5 back and forth back and forth from almost 2 months now! What can I do to break this cycle? Is this normal, to plateau for this long?