It sounds like you have more than dog troubles, and that is part of the dog troubles-an unstable family relationship, dogs, you, your husband and son.
For everyone to stay together, healthy and reasonably happy, your husband needs to be part of the solution.
He loves his dog, right?
He needs to understand that when this dog bites (breaks skin) all heck will break loose, legal heck, muzzle orders, restraints, quarantine, law suits, death (euthanasia order). He loves that dog very much (a very beautiful little dog, I will add) so he needs to figure out how to protect his dog from the very big mess that will happen (yes, I'm more or less speaking to your husband here).
Protection comes in many forms.
A calmer household, people getting along, respecting one another, reserving yelling and screaming or other obvious frustration behaviours for pillows (easier said than done) but something to keep in mind. Dogs do react/act out in the face of upset humans. So just like parents try to keep their arguments away from children's eyes and ears, same goes for dogs, especially sensitive dogs.
Management--keeping the dog away from events or people/other critters that will likely trigger a bite, or behaviour scary enough to cause humans to react.
Training--training will give the dog clear rules, guidelines, help the dog learn she has control over her environment and does not need to act out to be safe--in other words, training makes life just a little more predictable.
If you at all have funds for profession help, now is the time, before the dog bites. Muzzle training, dog in muzzle will buy everyone some time, and interim safety.