I’m sorry to hear of your troubles, Murphy!
It can be one or many short, less than 3 months post treatment, and then long term issues, more than 3 months, bothering you!
Ambian has its own side effects, including dysphagia. I’ve been taking it now for 8 years, which is really long term, but it’s better than not sleeping for me. Coughing up phlegm is common post treatment, and did, and still do all these years post treatment (almost 5) for multiple reasons. My epiglottis doesn’t fully close, so I aspirate silently a little, as was found during my swallow studies, which I had at least 4 at different centers, and had post treatment swallowing issues for years.
Have you had a recent chest X-ray to show any aspiration to the lungs? Not sure about the multi-vitamins, unless your doctor prescribes them as I’m not a big taker of vitamins anymore, but did for many years.
I went to swallow boot camp for a while, as I call it. At least 10 weeks, and was of much help. Many people I know went to such with the SLP.
Good luck with your ENT visit on the 2nd!