Suggest Treatment For Gagging And Spitting Of Phlegm

upon waking, have hard gagging that brings up phelm. This last anywhere from 30 minutes to a couple of hours. No pains other than the hurt from muscle strain of gagging.

It's been going on for about 2 months and getting worse. First the phelm is clear and then yellowish. There is no pink or bloody discharge.

The discharge is a thick slime sort of texture.