??? Waking up at 1am & 3.30am

I'm currently in my third trimester for almost every night I had been waking up at this timing due to heart burn even antacid cant help with my heart burn. I took dinner more than 3 hours before bedtime and I did not lie down immediately and I eat small portion of food. But my heart burn had been persisting for 2 nights I cant sleep already. Not sure is it due to work stress. Most of the heartburn accompanied by vomiting. Anyone facing same issue as me? I still must bear with it huhuhu ??