How To Fix Muffled Hearing In One Ear?

One of my ears is muffled and I can hear my pulse. When I bend down to pick something up, I get very dizzy. Sometimes if my head is tilted at a very particular angle, it is no longer muffled and I cannot hear my pulse anymore. This happened after I got out of the gym yesterday, and even a full night s sleep hasn t resolved it. Please help, it s very distracting.