Sounds like you might have a mild case of the flu, caused as you suggest, by a virus. It is a good sign that the stomach discomfort has cleared-up and the walk-in clinic people found your lungs to be clear. If this is the flu or a flu-like viral illness, the other symptoms should start to subside very soon. That your lungs were “clear” makes the feeling of “someone pouring hot water on my chest when I breathe” less worrisome, but if this is still bothering you when you receive this response, you should have the walk-in clinic staff re-examine your lungs and take a chest x-ray.
What you describe does not suggest something “more serious than a virus”.
Good luck.
by the way the stomach discomfort is gone now and only symptoms i have is feeling tired, dizzy, and the chest problem. i feel like i will start coughing soon because sometimes i feel my throat is kind of getting itchy.