Gosh I do

I've been miserable for months now. It started with a stuffy nose & itchy itchy eyes. Then I developed a headache. A horrible one. I went to the doctor for a possible sinus infection. He gave me antibiotics & a decongestant.. I took all of them. Now, weeks later, I'm still miserable. One of my nostrils is always stuffed up. Not usually both.. just one at a time. My nosy is ALWAYS itchy.. my eyes are so itchy I just wanna tear them out. And I have so much pressure in my forehead. It's just misery. My mother thinks it could be allergies.. since I sneeze most of the time like 25 times in a row. Anybody have any ideas? My head hurts so bad that if there's like a railing or something to hold onto, I have to, because I'm afraid I'm gonna fall. I just get very foggy.