Had severe diarrhea yesterday. today, i'm vomiting, constipated, hot and cold flashes and severe nausea. not pregnant. moved down south recently, and not used to the heat?

Your gastrointestinal symptoms are likely due to bacterial or viral infection. Covid-19 infection can manifest with such GI symptoms as well. If you think you are at risk of recent exposure, you should be tested jut to protect the elders around you although you are at minimal risk for significant disease. You just need good hydration, light diet in the next 2 days, take Tylenol for T above 101F.