I'm A 50 Year Old Woman Who Came Home Around

I'm a 50 year old woman who came home around 7pm after working and then attending a class at college. Made it through the door and wanted to jump in shower, but couldn't. My body began to shake and sweat profusely. My heart was racing and I had to sit down. My husband brought me something to eat, but in the middle of trying to eat it, I fell asleep. I'm now awake with a slight headache. The shaking, sweating, and heart palpitations have occurred before. Any idea what it is?