Diagnosed with viral syndrome sat. laying down i feel fine. standing up my heartrate jumps up to 130-140, dry mouth, extremely weak, headaches. pots?

Viral syndrome: It sounds like you may be dehydrated, so would start drinking water and continue to drink more fluids. Often when you have a viral illness you don't eat very much and have increased loss of fluids from fevers or vomiting or diarrhea. So start drinking healthy fluids!

Orthostatic dizzy: When heart rate goes up and blood pressure drops upon standing this is called orthostatic hypotension. In severe cases it can cause fainting. A heart rate of 130 is concerning and should be evaluated for pots but also other potential causes. In the interim always ensure that you are well hydrated, increase your salt intake and wait a few seconds after standing to take your first step.