ACV is great for heartburn/GERD, glad to hear it's working for you. What really helped me was reading Chris Kresser's series on GERD, he goes in-depth on the mechanisms behind it and ways to combat it with diet and digestive enzymes. I only needed papaya enzyme myself. I've been off of PPI medication for a year now and I had been on it for nearly a decade. Next step is to see if my Barrett's esophagus has improved, I'm due for a recheck endoscopy this year.
Here's a link to the series: Heartburn / GERD