@alisha-- If you sweat from your face, hands and armpits, your sweat glands might be overworking. You should go to the doctor and have it checked out. Your doctor can find out the underlying cause, because there can be many different reasons for it.
My brother had excessive sweating several years ago, his problem was an overactive thyroid. I know it can be embarrassing to deal with. But it happens to a lot of people and its treatable. Just keep some extra clothes with you at work and exercise. Also drink lots of liquids until its diagnosed and treated so that you are not dehydrated.