two month old night feedings and sleep

Sarah
So since we hit the 8 week growth spurt my little one has varied in the nap department and def regressed in night time sleep. She used to sleep a five hour stretch and then do a four hour and now we are lucky if she sleeps a three hour stretch when we put her down for the night. She has increased to five oz (formula fed) and tonight I gave her 6 oz because she seemed unsettled after 5 despite burping and sitting her upright for 30 mins (she has reflux)  she fell asleep quickly after this .. 
Is she that hungry she's jumping from 4 oz go 6 now ?? 
I began her nighttime routine at 7pm, bath feed and had her in her swing shortly before 9. I put her in her swing slightly awake and she settled herself and fell asleep. She's awake 3 hours later.. I gave her the soother in hopes that she will settle again..but have a feeling she will be up shortly.. 
I dunno what I'm doing wrong 😩