Head feels full, ears feel like they need to pop, muffled sounds, have to concentrate to hear what people say, constant ringing. how to get rid of?

Ear Infection??: Sure sounds like you've got the makings for an ear infection. Prevention of a full-on infection with fever, etc should include moisturizing, decongesting, and getting adequate rest. I often recommend Mucinex (guaifenesin) and pseudoephedrine along with hot steamy showers or a warm air humidifier.

Congestion: It appears that your eustschian tubes at the back of your nose are blocked by virtue of either allergies or a head cold. Try irritating your nasal passages with warm,salt water and spray a Nasal decongestant like neosynephrine or take a combination antihistamine and decongestant like contac or allerest(may cause drowsiness)orally.