WZ,
The 20lbs is a signifigant weight drop! I agree to see your ENT for a swallow study, and your willingness for a peg tube being your swallowing is getting worse instead of better. I heard this can happen in some long term survivors. I’m 10 years out myself, and not without incident, but I congratulate you on 15 years, minus any current difficulty, and this you shall overcome too!
Best wishes