Omg I had a cat, DustBuster, (he passed last year at 22 years old) that looked EXACTLY like that. It's like you took pictures of my boy there. A gray lion w/ a silver mane. Too bad feline supermodels isn't a real thing - your boy would easily make tons of $$ to pay the vet bills.
All wet food is the best way to get and keep your cats at a good healthy weight. And getting her from 16 pounds to 14 is a great start! I'm not great at math but a 2 pound loss for a creature that weighed 16 pounds is huge! Good job! :clap:
Feliway certainly couldn't hurt, but his behavior is normal for what's going on and the buprenex he is on. And I would certainly never go back to that original vet, you are right he sure should've been sent home on antibiotics after oral surgery!