I'm by no means an expert as you can see by my post on this page - tons of night wakings with my little one at almost the same age! I just read your post and sympathize but also sounded similar to my older one, she struggled with tons of tummy issues, including reflux. At 5.5months we started solids and all her night wakings disappeared. She was 10th percentile (so tiny, but not like yours, that's itty bitty!). Once the introduction of solids, the reflux started to get under control and she started to climb the charts, up to the 85th where she still sits now (2.5yrs - she's solid!). She was exclusively breast fed as well until the intro of solids.