I had white phlegm and thick. When the phlegm is green thats worse than white. Try the mucinex (over the counter) and see if it helps you. This dries you up from your lungs up to your sinuses. My doctor gave me 600mgs of mucinex
along with a antibiotic. Then another antibiotic to follow cleared it up completely. No coughing, no phlegm, nothing anymore. Talk with your doctor to see what remedy fits best for your situation.
hope you feel better soon,
Kathy
I would like to mention one more thing. When my doctor tested my sinuses, they hurt! I knew it had to be the culprit of all the issues going on with my lungs too. I don't take claritin/clarinex or nothing like that cause it relaxes my lungs too much and it seems to get my lungs congested too. If I feel stuffy, I turn on the shower and steam up the bathroom till it fogs up the mirrors and sit in there for 15-30 minutes with the hot shower going. This not only helped my sinus congestion, it helped my lungs too.

My boys cannot take decongestants due to their condition and when they are stuffy, it seems to go into their lungs (which is a constant problem anyway from the diagnosis they have) so we get a anihistamine spray that is NO DRIP. You will find this works better all the way around when allergy season is at its worst.
Sorry for a long post.