Big hugs. DD2 did this for 3.5 months It was a huge shock as I don't recall DD1 doing it, or maybe I've just chosen to forget it

Will find a post I wrote awhile ago to Lulu as she too was having issues with her DD3.

In the meantime, add 'glue ear' to your list to ask the GP. I've had a few friends with babies who slept terribly and they had glue ear. Two of them had to get grommets, one of them cleared on their own. Sleep magically returned to normal!

Will BBL but just quickly, teeth can definitely cause that much pain for some babies and often only effects them at night. Laying down causes the pain the increase. Also, when babies are having big growth spurts (outside of WWs too), they struggle with sleep as they're thinking too much and often practicing in their sleep. Sitting, rolling, standing and crawling have caused issues for both my girls (not badly for DD1 though).

it's tough. I'll never forget the hourly wakeups with DD2 night after night. It sucks!