You lost EIGHTY pounds in two weeks? If that's not a typo, you need to get to the emergency room as soon as possible. If you mean eight pounds, that's still significant, but not an emergency.
It really sounds like you need to see a doctor soon. They'll want to run some tests so they can rule in/out possible causes. Without those tests and the results, it's really not possible to determine what's going on with your body.
Have you seen your doctor?