Ask HN: How to get rid of reflux acid
Raise the head of your bed an inch or two. Sleep on your back. Gravity will help keep the acid where it belongs.
Sleep on the left side of you're able to.
Go to a physician.
Don't rely too much on things that contain calcium carbonate because you can give yourself a kidney stone.
If they throw pills at it, get a 2nd opinion.
A person I knew was on prescription antacids for several years & was starting to develop stones. When the MD prescribed another pharma, I asked her to visit a different MD. The 2nd MD ID'ed her weak esophogeal sphincter, scheduled & performed an out-patient procedure to add a small suture to tighten up the leaky seal and she no longer required the very expensive pharma band-aid(s).
Consult a physician, rather than asking for advice here. I'm sure the replies are all well meaning, but what helped for someone else might not help you.
Best to seek professional medical advice that can be tailored (I hope) to your situation.
Avoid acidic foods. Eat cucumbers, greens, etc which have a cooling effect on your stomach.