Help please

When I was 29 weeks and 5 days until I was 31 or 32 weeks I had gastroenteritis, even 33 & some of 34 weeks I was recovering from the vomiting, diarrhea and even the inflammation inside my stomach; as I had it severe compared to my boyfriend who it for 2-3 days and was fine within the next couple days. When I was recovering, I obviously still felt weak, tired and had awful acid reflux. I’m 34 weeks but will be 35 weeks in 1 day. What can I take that’s safe to help with the acid reflux, it’s annoying the hell out of me tasting the acidity in my mouth at night constantly and occasionally throughout the day. All my OB/GYN is saying is to take tums but that’s not working. I’m 19 so sometimes the people in my town don’t take my seriously when I need help. Mainly cause I had to go to emerge 3 times to finally be prescribed pills when the first day I went to the hospital I puked 20 times (mainly blood & mucus) and couldn’t stand up. They gave nothing except an IV to give me fluids to go home. By the third day, I got pills and actually got a blood test to find out my stomach was inflamed causing the acid in me to worsen; making me stay up all night in pain. This was a month ago but obviously the acid still is doing something to me, mostly at night since that’s when it happens the most. I just want suggestions that are safe to take for a pregnancy or certain foods that may lower/help with it. I’ve taken 3 to 5 tums which the maximum is 5 on the bottle and I’m out of options. I’m praying that there is a way to fix this so I’m not suffering in case this won’t go away even after the baby is born.