I am new to the dysautonomia symptoms, but they are debilitating. I have started carrying the ice packs that you break and then they get cold, if that makes sense. So I have something cold available when I feel over heated or faint.

Hope you get better soon. For overheating get a usb charged mini fan u can take and charge when needed. For dizziness try B1 supplement and orange or lemon flavored (sour flavors reduce nausea) , sugar free gatorade. Hydration will also keep the headaches in check. Get up slowly from sitting or when changing posture. Take care