I haven't had the surgeries you have had, but I did have an excisional biopsy and since then I've had a hard time eating. I don't know if it has to do with the biopsy or with my other medical issues, the medications, the worry, or just bodily changes.
I do know I've lost about ten pounds now and I'm around 96-98 pounds now and I was told the other day that I had better force myself to eat and to try and get my weight up (the nurse practioner suggested I try for about 110 pounds which sure got a raised eyebrow from me!), but she suggested it because she said if I get very sick, (sicker than I am currently) that I would need that extra weight and strength to help me get through whatever I have to face as far as fighting off and coping with the possible sickness or whatever it is that might come down the line next.
So....... I'm in the process of looking around for good, comforting, palatable, filling, weight gaining things I can find to eat. Being a vegan, this does complicate things a little bit, but I know that I could do better in the finding recipies and things I can eat that will help me in this weight gaining thing.
I hope you do the same and find good things to eat and get busy eating them. :)
Best wishes and good vibes.