Fast food restaurant made me sick

My fiancé and I are on a road trip right now and had to make late night food stop. I knew it was risky so I just got fries and chicken fingers. They tasted a little weird but I thought it might have just been my taste buds from not eating fast food in a while. I didn’t eat the fries but I did eat the chicken still.

Within the hour my stomach was upset, and my mouth tasted like the funky taste of what I ate.

I don’t think I got food poisoning, but maybe the food was cooked in old grease?

Does anyone have any tips on how to settle an upset stomach. It’s now the next say and I can still taste it a little (I have brushed my teeth, altoids, soda) literally have done everything.

Anyone have any tips?