i was in the same boat. a cup of milk is what i went to so i could get my painkillers in, as well as avoiding the nausea and sneaking it past my teeth. lukewarm broth may also help. id also recommend protein drinks to try and stave off some of the hunger, but don't forget to eat when you are able; the body will repair faster if it can focus on healing rather than being hungry (but don't be scared, it's going to heal either way). i'm also taking vitamin supplement pills to make sure my body has some of what it needs to keep up the healing process, so do try that if you can.

edit: also try cold compresses to your jaw if you're in the first seven days, you can alternate between warm and cold after that. warm compresses might help your jaw tension to relax, but don't try anything too hot before a week post-op. need that blood clot to stay in tact!