I constantly had acid reflux for 15+ years, ranging from being mild to keeping me up at night. I eliminated several foods from my diet, tomatoes, most fruit, spicy food, etc. I was constantly taking Rennies or other antacids.
I was staying with family over Christmas in a remote area with no shops nearby. There was no coffee in the house and I went the week without it. As the week went on I noticed my acid reflux getting better and by the end of the week it was completely gone.
Since then, I have stayed off coffee and am able to eat all foods again. Now and again I might get a some mild reflux, but all in all, quitting coffee got rid of it completely.
Just posting this here in case it helps someone else.