>>35314829I feel for you and I wanted to give you some possibly helpful advice.
Pet stores like PetSmart and Petco sell a dog mace (citronella based) that is relatively cheap and could come in handy if you run into the dog again. You could use regular mace but keep in mind it's much much stronger so be careful if you use it. Make sure you aim it directly at the dogs nose, NOT it's eyes, to incapacitate it. You could also carry a can full of pebbles to shake at the dog - the loud sound sometimes startles them and keeps them at bay.
You could also buy a prong collar and put in on your dog inside-out - your dog won't be hurt by it, but if another dog attempted to grab them by the neck they would get a mouthful of metal prongs.
People who don't properly manage their dogs are my worst pet peeve, dogs are my life (I'm a trainer in-training) and these people make responsible owners look bad and cause their own dogs to suffer in the process. I hope things improve for you!