eat light:

Vaseline. get a jar of the straight up vaseline grease (ew, I know.) and about once a week or so, take a finger full and wipe it on the cat's upper palate, just behind the front teeth. He can do nothing at this point but lick it all off. Depending on the cat, you can generally avoid getting bitten by wrestling him into a football hold, then using your thumb and forefinger of your left hand, press on the corners of his mouth - you can slide your finger and thumb between his back teeth long enough to shove in some vaseline with the little finger on your right hand. He'll make a face and hate you, but he'll eventually lick it all off. If you were feeling particularly generous, you could mix it with a little of the sauce from his wet food first. Or, alternate with peanut butter or some similarly sticky substance that he likes. He might tolerate the vaseline better if he thinks he might be getting something yummy. My stepmom used to do this with a hairball-prone cat of ours, and it worked miracles. And, at least it wasn't a puddle of piss.
Oh yeah, tell the vet about the puking. They may have some more tricks for you, and cats generally don't puke that much unless there's something else going on. Or they truly hate you.
Good luck, and my sympathies. Cats can be wonderful, and they can be spiteful and (seemingly) purposefully nasty.