What Causes Excess Mucous In Throat Despite Suffering From Asthma?

Hello i have some phlegm (i think) stuck in my throat everytime i try swallow it like pops back up... I have a drip at the back of my throat at times and sometimes i cant swallow and get a bit panicky... Ive lost my job and cant afford to go to the doctors. I also have asthma. Its really annoying and have to sleep sitting up. Do you have any advice?