I use Jay Robb chocolate or vanilla whey Protein powders made with stevia.
They in my opinion they are light and not overly sweet.
You can purchase individual packets to try.
They make other flavors I believe.
Good luck in finding something you like.
Good luck on your surgery and you can get through this. I am just about done on Tuesday and surgery on Wednesday. It will be great at end of the day on the 29th because you'll be done and onto surgery on the 30th.