Sounds like a sleep regression. Hang in there. You're doing a great job.
Thicker or more food might help with sleeping through the night. I let my baby play more or do tickle time and make him constantly stand up or something to help make him more tired. Also my babies have always slept better in just a diaper and soft furry blanket
My 7 month old started doing this about a week ago, too. She had been sleeping really well before, but now she's struggling to fall asleep and not sleeping through the night.