I think she needs a trip to the vets for a complete exam to rule out any physical reason for all these symptoms.. She could be really sick and these are the only ways she has to alert you that something is not right. I would have alarms going off all over the place if it were my baby. Cutting down on food intake and drooling could mean bad teeth and she is in pain.

It may be serious depression and if it is she needs help for that, maybe medication or some changes in the house of some sort. This baby is screaming at you for help!! Please get her to a vet ASAP!!!!