I would get a second opinion with a vet.
A cat should never go more than 24 hours without food as their livers do not metabolize fat energy well. I am shocked that a vet would not consider this
.
Also antibiotics are notorious for causing tummy upset in cats (and humans) so that could be another reason your kitty is not eating.
Just imagine if you just got your teeth out? Would your dentist prescribe hard, crunchy food or soft food for a few weeks until you can bear to chew again? I highly recommend a quality canned food such as Wellness, grain free, Natures Variety, Instinct, and Organics by Nature.
I don't think a cat has the mental capability to play on your sympathies. I think your kitty has an upset tummy from the antibiotics or has/has had pain from eating kibble.