I know from having GERD (Gastro Esophageal Reflux Disease) that two of the things that you need to stay away from if you have mild to moderate GERD are Fatty Foods and Coffee (because it is acidic). If you are drinking a whole three cups of coffee, surely you are taking in a lot of acid!! Couple that with Fat and there you go....
perfect storm for getting nauseous. You might want to look into whether you have mild to moderate Reflux
issues. They can manifest in many different ways, nausea being one of them. I for one CANNOT drink
more than 1/2 cup coffee and ONLY on a FULL stomach, so that the acidity is manageable. If I stay away
from acidic and fatty foods I am not having the reflux and nausea. Btw, this took me a long time to
totally understand as well. Finally went to a Gastroenterologist and then did a lot of own research. Hope this may help you.