Both really great suggestions! It isn't easy to think of most simple things when it's your own dog freaking out!  Maybe the dog is picking up on my stress, also since it was always ok to greet other dogs on walks.

I don't want the dog to get so scared going for walks is a source of stress. Reducing anxiety seems like the best first step. A refresher 'training' might be good but, I don't think this dog is going to easily do that when so over-stressed. Maybe after we get the dog back to knowing walks and fear don't go together treats would help before it becomes a bad habit. It's manageable for now just a very unexpected and embarrassing change because the dog is so sweet natured.

Thanks for your suggestions!