This happened to me too, but in both ears. Hit my head, my ears clogged, then unclogged for a week, and then clogged back up again. At first they were 24/7, but gradually became less and less severe. I am now 2.5 months out from my hit and they still clog, but only when I am dehydrated and/or am doing something strenuous.

My guess is that it is an inflammatory response of some kind. I know that it feels maddening - it is probably the worst feeling in the entire world. Give it time, rest, etc.

One thing to note - do you have any thin, clear fluid coming from your nose, ears, or down the back of your throat? If so then you need to get checked by a neuro immediately, could be a CSF leak.

Also, you may have agitated your sinuses. Not sure if it is coincidence or not, but after I hit my head my sinuses started producing thick mucus in the back of my nose/throat which I am assuming accounts for the blockage that I still feel.