Aiyoh I feel you, GERD during pregnancy memang torture especially when you're vomiting on top of it! Honestly I'd say best to check with your doctor or midwife first about what's safe to take during trimester 2, they can recommend the right antacid for you, because different ones are okay at different stages of pregnancy. In the meantime, a few of us tried eating smaller meals, avoiding spicy food, and sleeping with extra pillows to prop ourselves up, which helped a bit lah! Also try to stay upright after eating if you can, not lying down immediately. Hang in there, hopefully it gets better soon!