I sometimes feel like this too, I think it's because for me, everything in my life changed all at once. I had the surgery, a few days later I lost my job, and a few days after that I moved house! So everything in my life was different AND I was trying to deal with my new tummy. I was pretty emotional haha.
Anyway now I feel great, never been happier.
I think it's something most of a go through after surgery and it's pretty normal.
Jut focus on the good things, you may not be eating what your family eats but soon you will be able to do what they do (ride bikes, play in the park, run around outside ect) and which would you prefer?