I certainly can relate with you and the weight gain. I barely ate anything except ice cream and mixed nuts for at least 6 weeks after my surgery, and not much of that. Once I started enjoying food again, I haven't stopped eating and have gained 4 pounds. I am upset with myself for doing that. I had done so well before the new knee and had lost about 17 pounds. I do not want to put that back on!
My Brat showed her anger last night after my day and evening last night. I iced as shortly after I got back home, so I'm sure it would have been even worse without the ice. My swelling is up 3/4", so I know she's unhappy. I'm icing right now. This should calm her way down. Neither knee has liked being down for a while in at least 20 years, so it's nothing unusual. But, once My Brat is healed I expect her to not care about that anymore!
It will be quite a while before I hit 10,000 steps again, but I'm getting up in numbers every week. One day! Each painfree step I take is a blessing!