it just sounds like your sinuses are clogged- head on over to the allergies board and you will see the array of annoying physical symptoms that allergies can manifest. fortunately there are tons of treatments out there.
if you can, see a doctor. your response to an antihistamine will include factors such as how severe your allergies are and what type they are. i have seasonal allergies and only zyrtec was effective for me, and i tried allegra and claritin with no success. they all work in slightly different ways and that's why one can do nothing and another can do wonders.
a humidifer could help with clearing your head. to get mucus out of your throat, try an over the counter nasal spray (like simply saline, it's just salt water) it washes out the bacteria that's sitting in your nose and irritating you and it immediately relieves swelling, and you can use it often and it's not habit forming. good luck!