About a year before going primal I read "Primal Body Primal Mind" by yeah, I don't remember. One thing the author mentioned was that heart burn etc is often caused by a lack of stomach acid and taking anti-acids actually makes it worse. She suggested taking suppliments to increase acid. Not saying it will work for you but something to think about.
I have had heartburn twice since going primal. Both times were after I ate non-primal foods. I'm sorry to hear you are not having similar results.