Tell them you would like for them to prescribe Deramaxx for the pain, and Metoclopromide for the nausea. There is no reason for them not to give you the drugs.

If the abdomen appears swollen then a trip back to the Vet for a check should be made.

The nausea should not last for more than 12 hours, and with a pain drug the dog should be comfortable.

Don't put anything on the incision, until it's healed. They did give you antibiotics right? If not find another Vet quickly.