Gaviscon liquid was the only thing that made me sick in pregnancy however, the Gaviscon tablets worked a treat - give them a try. They were available on prescription too.
The pill previously mentioned from your GP is called Ranitidine and it worked brilliantly for me, each pill giving me up tp 12 hours relief, I could time the pain returning literally every time. Since my pregnancy 1 year and half ago I have seen other indigestion tablets over the counter now that have ranitidine in, but obviously the dosage may differ.