Aih, heartburn dalam first trimester memang sakit hati! Try makan kecil-kecil tapi frequent saja, and avoid spicy or oily foods, a few of my mum friends swear by makan plain biscuits atau toast je before tidur to help dengan discomfort malam. Drink plenty of water in between meals (bukan during) and try tidur with your head elevated, helps dengan gravity kan. Since this is bothering your daily activities, do check with your gynae or doctor, they might recommend safe antacids for pregnancy or suggest other ways to manage it. Mum groups usually say it gets better after first trimester, so hang in there!