hey hon, lots and lots of (((HUGS)))
I agree with Katy, this is not your fault at all!!!!!
It does sound like discomfort to me hon. Waking up so often and having trouble resettling. How long has she been having oatmeal at night? Does it seem worse ever since? At her age, especially being a refluxer I would definitely advise holding off on solids at night. Also, cereals can be really hard on the tummy, it is usually best to start with fruits and / or vegs. Also solids, especially cereals can worsen reflux.
Is she on reflux meds at all?