Eating smaller meals slowly and sat upright.
Don't eat anywhere near bedtime.
Not drinking with meals, only before and after.
Find your trigger foods if there are any (mine are bananas, chocolate, garlic and onions).
MILK MILK MILK!! I drink pints of the stuff and take a glass to bed and get one through the night if I need it when I go to the loo.
Getting up and walking around during the night when you get it throughout the night.
I really sympathise with you, heartburn has made me sick several times throughout pregnancy. I'm 36+6 and as baby is starting to drop I'm noticing a slight improvement. Such severe heartburn is miserable! Hope you feel better soon 