I mixed FairLife 2% milk with chocolate Unjury powder. It tastes really good. FairLife Milk is a good protein source too so you get more bang for your buck.
I have had a similar experience. I lost 30# between Sept. & surgery( 12/29), BMI= 35.
1 week after surgery, I had lost 4#. They said pre-op loss and lower BMI might result in slower progress.