Hi there
Just want to send you a hug. I understand how frusterated you must be.
My Dd is 7.5 months and it takes her 40minutes to finish an 8oz bottle. As for solids I have to sing to her to eat. It drives me crazy. The only thing I can think of is, have you tried a faster teat. It sounds like something is going on with your lo. Tommy pain, reflux? I am sure someone will respond soon. In the meantime, have you tried to sneak some milk in her food. I know it is not much, but it does help. When my lo refuses to eat, I give her some toast dipped in milk.
Hang in there