Choking with acid reflux

I’m so upset! My 8 week old has acid reflux. We have to have hold her upright after feedings for 30+ minutes and 60-90 minutes after her bedtime feeding because she always eats more. She is taking medication for it given by our pediatrician. Tonight we held her up closer to 60 minutes before laying her down in her bassinet (that is slightly inclined under mattress) and I just caught her literally choking! Thankfully I saw her struggling to get air and moving her arms in a panicked way and picked her up immediately. It took her a little while to actually cough and get air in my arms. This was so upsetting to watch and I’m afraid I will never sleep again bc I don’t want to miss this happening in the middle of the night! This has happened way back when she was 3 weeks old but has not happened since so I’m surprised it happened again. Anyone else have babies that have done this? Anything else you’ve tried to help? Any peace of mind you can give me will help!