I feel for you. Throughout the entire 2nd and 3rd Tri I have had miserable indigestion and heartburn, and its gotten terrible late in the 3rd tri, to the point where I can't eat anything. The other night I ate dinner at 6-ish and woke up with horrid heartburn at 2a, I was so ticked!
My doctor recommended I try Mylanta (the drinkable kind), instead of the chewable pepcid,ect, and it does seem to at least help a bit, so I hope maybe that will help you too.