I woke up with my ears feeling full and my hearing was muffled. What is wrong with me?

Ears full. The most common cause of insidious onset of ear fullness with decreased hearing is congestion in your eustachian tube, usually due either to chronic allergies or to a recent cold. There are no really good treatments for this, and generally you just have to wait it out. This condition is usually associated with a feel of pressure, but only in severe cases is their actual ear pain.