My baby depend upon formula milk. After 3 months, she suddenly stops having the formula milk and it is much hard to feed her milk. As I unable to produce enough breast milk, she shows interest only on breast milk. She refuses constantly the formula milk, I visited her doctor, she is fine according to the doctor. Please help me to know, why she refuses the formula milk all of sudden, and how to feed her. Because she is refusing the milk and being hungry for 6 hrs.