Hello:
I suffered with Fibromyalgia and also Reflux for decades.
I still suffer with Fibromyalgia, but it is now extremely rare that I have any reflux symptoms.
When I did, I took a daily OTC: Prilosec, Tagamet, Pepcid, (Famotidine)
This treatment worked for me. However, I do not require treatment now for Reflux or GERD.
I began a very low carbohydrate diet three years ago (Keto Diet), and my Reflux symptoms essentially were eliminated.
The Keto diet is not for everyone, I recommend a consultation with a health care professional prior to any diet change.
That said, it worked for me resulting in weight loss, and elimination of the routine Reflux symptoms. Now, I may experience reflux symptoms once every 6 months, and only then if I do something like a heavy meal of extremely spicy content or high Carb content.
I hope this may provide you some help with your issue, but again, I recommend the input of a health care provider.
I wish you only the best.
Regards