my throat is very sore, what should i do?

So my throat has been irritated for literally over a year now. It started off where my throat seemed cloggged (like it does before you clear your throat) but clearing it wouldn't help fully, so i would cough lightly, sort of like saying "EH-hm" but with a little cough to it, every few minuets or so. i got so used to it that i would do it throughout the whole day and not even pay attention (although i know it annoyed my friends and family) and that went on for a few months. recently, ive realized it works if i just clear my throat and cough with my mouth shut. I dont know what to do, i asked my doctor about it once and he said my throat was very red and irritated and to gargle with salt water and eat cough drops for a couple weeks, but it didnt help! some nights it gets really bad and my throat never seems to unclog, and i cant fall asleep for hours! what is this, and what should i do?