What's wrong with my dog?

I am sure this is traumatizing for you all! It sounds to me like your dog is losing her sight. It puts her on constant edge, not mean, just to protect herself from things she can't make out and noises not familiar with. When one sense goes, another becomes stronger. Since a dog has excellent hearing anyway, this is becoming stronger and she is hearing a lot of things that are scary along with not being able to see. Please, soon, get her to a vet and get her checked out. Another possiblility is a small stroke, or a form of animal alzheimer's. Please get your baby to the vet soon. If nothing can be found, you cannot have a dog biting like that. You know what you'll have to do on that before it hurts a baby or child or and adult very, very badly and it isn't a family member and they sue your tail end off. But keep the dog away from everyone unitl you can get it to the vet and let the vet know before you go in what is going on so they can be on guard for the dog to be scared and they will be ready for the dog to try to bolt or charge them. Please, let them know before you go in! But get her to the vet. If I can help later, after a diagnosis, feel free to ask. Best of luck to you!