Ringing in my ears will it go?

i have had ringing in my ears for a bout 3-4months now and the ringing is backed y a constant clicking sound coming from my ear. when i originally noticed the ringing i went into the doctors the next morning and found out that i had a serious cold that left me full of mucus. i was told that the ringing would stop sfter a few days. but after a week it was still going on when going to the doctoer again i was told that i had a build up of mucus around the eardrum causing the ringing, and also the crackling was due to air going through it. i was advised to do some things but due to college i had little time to do them so the ringing is still continuing. also a few days befor the ringing i was at a party and inhaled some nitrous oxide from a balloon, it was my first time and i know now that it can cause a ringing in the ears after excessive use (which i certainly didnt do) its also on both sides and changes pitch from time to time and gets louder if i push on my head behind my ears