I Went To Del Taco Yesterday And Has A Chesee

I went to del taco yesterday and has a chesee quesadilla and as i was swallowing the last bite tasted like burned or melted plastic. And last night and all day today my stomach feels it's burning like stomach acid and I've felt nauseous and have had diarrhea all day but the pain is still there. And now there is a soreness on both sides of my back as well.