I totally had a stomach virus earlier this summer also and it freaked me ooouuuutttt. Like seriously for reals. Then I learned that in fact, many stomach bugs are way more common in the summer because it is hot and food is left out, and ventilation sux and bacteria grows like crazy. Hence, everyone gets food poisoning.
I went to the doctor and made the mistake of getting testing done. Don't do that, lol. Things came back abnormal like the white blood cel poop thing (sorry tmi) and I was totally convinced I had colon cancer or Crohns disease. My doctor assured me that really the test results were consistent with food poison gastroenteritis, but I felt like I was going insane until I repeated the tests when I was feeling better and everything came back normal.
But seriously, what your describing is exactly what I felt like. Sharp stomach aches. For me they felt like waves. Like sharp waves of pain. And I felt like I needed to puke but I didn't (I also have emetophobia). Seriously don't worry. This is def summer time stomach probs. :)