What Causes Clogging Of Ears?

i am recovering form a sinus infection, and my ears are clogged. it feels like my whole head is in a fish bowl. everything is muffled, and its driving me crazy. i head taking a 90Mg dos of sudafed (Pseudoephedrin) will fix this?? please help!!! I can t live like this and am starting to freak out. note: no pain per se at the moment.