Ears can cause the symptoms you are describing. DS went from a great sleeper to awful in a matter if weeks and i have only found out in the last few days its a chronic ear infection. I was given a nasal spray to help until he has grommets put in and suddenly he sleeps again. No back arching, rubbing at face, screaming and coughing all night.

I found using saline sprays up the nose helped a fair bit along with a humid room. Allows the lo to breath easier. Otherwise look at the infant gaviscon which helps with reflux at night.