I have been dealing with muffled and pain in my left ear ever since I wore a pair of ear plugs and I don't know what to do. The pain and muffled hearing started after taking my ear plugs out. I am Autistic and I have FASD along with ADHD.
It could be, but that is very unlikely just because of ear plugs. Try popping your ears, clearing the ear pressure from the middle ear as you do in a plane. Hold your nose and pop your ears, then swallow a couple of times to equalize the ear pressure.