Now you know why airline pilots don't fly when they have a cold.
I was in exactly the same situation as you, I caught a cold in south east asia and then decending rapidly on a flight into singapore both my ears clogged up and frankly I thought I have gone deaf.
It took a couple of days for the symptons to ease and nearly a month for my ears to return to normal.
I had a gp/md and ent check my ears for middle ear damage, but thankfully all was clear.
All they recommended I do is use a standard over the counter nasal spay (the same you may use to treat a cold - oxymetazoline hydrochloride based) which I believe did help.
If you travel alot be careful on aircraft that fly below 10,000 feet and consider carrying ear plugs (sometimes called ear-planes) to help control the pressure in your ears.
Mike