Hello, I had the same problem.
Discovered that I have a food allergie !!!!
It is not nice but you can solve the problem by finding out which
foods cause the tighnes, mucus and coughs, and ovoiding them.
When you do a search for foodallergys you wil find that the lungs
is a specific area where the symtoms manifest.
Even that peaple are misdiagnosed for astma, but in fact are
allergic to specific foods.
Watch out with chocolat, it is one of the allergic foods.
Also found a solution when I have an attac.
Half a teaspoon of Backing Soda ( Natriumbicarbonaat ) in a glas
of water, counteracts the attac and I experience immidiate relief.
Most probably an food-allergie.
Ik had the same ( very seriuous ) and have found that I am allergic
to eggs, diary and a lot more.
I read in Prevention magazine that coughing can be controlled by eating dark chocolate. I bought a bar of it and broke off a square and ate it every time I felt like coughing after eating. It cleared up after a week of doing this.