lump/phlem in throat

I have a persistant feeling of a lump or mass being in my throat - jnot deep down in the throat but rather just at the back of my throat on the right side behind where your tonsils are. It feels like phlem. When I try to clear my throat or cough it up  I hear/feel a rattling senstation like loose phlem is there but nothing ever comes up no matter how hard I cough or clear my throat. Sometimes it makes me feel like I need to blow my nose on the right side but nothing ever comes out from that either. It doesn't bother me all the time, mostly just after I eat - I will eat and do not have any trouble actually swallowing my food but after I finish my meal then the sensation of the phlem starts and I have to clear my throat over and over, sometimes for 10 or 15 minutes before the sensation passes. The really weird thing is it also seems to be weather related! Whenever it is cold and damp, the minute I go outside into the cold and damp air I get the same sensation as after I've eaten. There is no pain associated with it, just an annoying feeling. This all started after a serious bout with bronchitis that lasted for about 6 weeks that caused me to cough so much it would make me cry my rib cage hurt so much! When the bronchitis cleared up, I was left with this lump of phlem in the throat feeling which has been persistant for about a year now.  I worry that I may have damaged my throat from all that coughing? Any ideas what this could be?