welcome to HCM!
Have gone through your question and fine that you appear to be suffering from intestinal infection and severe gastritis
. due to infection, you have fever and hot flashes and diarrhoea.
You have not mentioned about treatment and investigations. I would advice you to see a doctor - as now it is five days and you have symptoms.
Had I been treating you, I would advice you antibiotics like cephalosporins and metronidazole
combination along with some antacids like pantoperazole and domperidone
combination. With this I would ask you to get blood test
done. An Ultra sound
abdomen will rule out any major cause of worry.
Another important thing is that you must continue to eat and drink water to maintain hydration.
Hope the answer helps you in getting better.
Feel free to ask if you have more queries.