Sorry to hear your story. I have something similar and not been able to get rid of it either. I tried the spray, and treatments for GERD as well. Clearing my throat often seems worse after meals and is less in the evenings. I'm also on pills to reduce stomach acid as the blood thinner I'm on can make my stomach bleed. What seems to be lacking is a cure--pharmacueticals never seem to cure anything. I developed my problem after I had a stomach ulcer back in 2017 but that does not seem to be related as once cured the same issues persist. Perhaps it's food related, I really don't know. Given that half the time we don't know what's added to our foods these days...
I hope you find some relief/solution. I've just learned to live with it for now.