Did you read the post about percussive therapy. It's something a respiratory tech (pulmonary tech) might do, but you can do it at home. Look back at my posts. Heck I'll post one again.

This shows the six position.
[link to www.uwhealth.org]

Anyone who has a cough and mucus is coming out and having trouble NEEDS to do this. Maybe in ten years it will be in parenting books, and the next generation will think of it as normal.

That tapping is far better than anything to help remove the mucus. Would you rather wait for cough medicine and pills to slowly work? Or would rather get immediate relief? It's up to you.

Anyone can be trained to do it. Heck a child could do it for you.

When someone is in drug rehab, their liver is a mess. Kidney too. Both filter the blood especially the liver.
In Germany they give milk thistle to detox.

I know personally of a very bad alcoholic who was dying and had a matter of days to live. She took milk thistle and it gave her a month to say goodbye. It's powerful and cheap.

If you were smoking some drug, you'll have tar in your lungs that got deposited as particles in mucus and slowly will get express.

Sounds like an full blown bacterial infection. Drug users of long duration sometimes get fungal infections in their lungs because they've abused their bodies so much. Your symptoms sound like aspergillosis.
They have to learn how to expel mucus because their lungs are damaged. Seems dumb, but try it. Seriously.

[link to en.wikipedia.org]