One Step Forward, Two Steps Back

For the past two weeks my LO (now 4 weeks old) has been down to only feeding once through the night. She was consistently feeding at 10 pm, 2:30/3 am, 7 am. She is EBF and does a breast milk bottle every once in a while.

Yesterday we took her to the doctor for reflux, which she's struggled with since birth. We'd been using gas drops but they just weren't cutting it, so the doctor put her on Zantac and had us add cereal to her bottle. We did the Zantac at 7 pm and added the rice cereal to a bottle that we did at 10 pm. During the night she woke up at 1:45 which I thought was just a little early for her 2:30/3 feeding. I did a 45 minute breast feeding session and she went right to sleep. But then she's woken up crying and hungry at 4:15 and 5:45. I tried to let her self soothe, checked her diaper and rocked her those two times thinking surely she wasn't hungry. But both times she needed to be fed, which I did for 15 ish minutes hoping it'd hold her over until 7.

Has anyone else seen a step backwards in sleeping/feeding when you added in Zantac or cereal to your milk? I'm hoping maybe this is just a growth spurt and that we haven't totally lost our one feeding during the night. That was so crucial for me to feel rested during the day. Thanks for any advice!!