Hello and hope you are doing well.
There are tubes called 'Eustachian tubes' which connect the middle ear to the throat, this balances the air pressure in the ears. This tube can get blocked due to infections of the throat, which can give lead to a feeling of fullness in the ears. This can also result in infection of the ears. The blocked ears can be opened up by the valsalva maneuver, where air is blown into the cheeks against a closed nostrils, this sometimes helps to open up the tubes. Steam inhalations and warm salt water gargles can help clear the tube. Please consult your family physician.
Hope this helped and do keep us posted.
Sounds like an issue with your eustachian tubes.