Stomach flu or just fear?

Well during today i went to seven eleven and bought a chocolate bar and some Milano's. I ate some and during later i started not to feel good. I started being scared of throwing up and felt really nauseos and began not to eat as much. I can eat a little bit not as much. I'm shivering a little but i think thats because i'm scared. I really do have a fear of throwing up and i always mistaken my burps for puke