Just an update. I started with the Gaviscon double action (pink bottle) and that helped for a while. Once I started carrying the bottle around with me, my OB ok'd Zantac. I was taking 2 a day for a while. Then I needed to top up with Gavsicon or Tums, as the Zantac would only last 6-8 hours rather than 12.

I'm now on a prescription medication Omeprazole, which is working well so far.