My ear feels like filled with water, and hurts. there is no actual water though, what can it be and how to get rid of it?

Fluid: While it isn't actually water, it is usually fluid behind the eardrum. The ear has a tube connected to the nose and throat and when you have a lot of sinus drainage, as with allergies or a cold, you can collect fluid behind your ears that makes it feel like your ears are full. Sometimes a decongestant or a prescription nasal spray is necessary but you should see your doctor to be sure.