I have some issues the 'extra' phlem as well. One of the things that helps me at times (better than never?) has been guaifenesin - an active ingredient in Mucinex and in some generic cold meds, which are over the counter meds.
I have a horrible allergy to rag weed, and it's in full bloom right now here!! AHHHHHHHH!!! There are no other medicines that help me with this at all, so I'll take the little bit of help that I get from the Mucinex.
If it's reflux, then you have too much stomach acid - but too little stomach acid gives the same symptoms. There are some at home tests you can do to determine if you have too much or too little stomach acid. If you have too much stomach acid, you will need to take acid reducers, but if you have too little, then you need digestive supplements.
Home test for stomach acid:
hansacenter.com/simple-at-home-test-for-low-stomach-acid/drjockers.com/5-ways-to-test-your-stomach-acid-levels/