Word for the vomit-y feeling you get for eating too much fatty food

Here you go:

nausea, n.
1. a. A feeling of sickness with an inclination to vomit; an occurrence of such a feeling.

["nausea, n.". OED Online. December 2015. Oxford University Press. http://www.oed.com/view/Entry/125412?redirectedFrom=nausea (accessed January 01, 2016).]

Don't spend it all in one place.

queasy

means suffering from nausea, a stomach distress with distaste for food and an urge to vomit.

"...if I eat any more meat, I'd vomit. I'm feeling queasy."

A good but more formal synonym is

nauseated

or more commonly

nauseous

Note that the latter means literally 'nausea inducing', but commonly used instead to mean 'having nausea'. I can't recommend one way or the other, because though 'nauseated' is correct to mean 'I have nausea', it is not as often used as 'nauseous' for the same situation.