I am sorry to hear about your situation.
It is rather rude to ask that your husband and children be in the photographs, and exclude you. You are a part of the the family and are being treated as if you are not a part of it. In a way I agree with what your husband said, "It's either all of us or none of us!" but I think saying that would cause some problems. If that is how your husband feels, I would ask him to speak to the family and say that he does not think it is right that you and the other in-laws are excluded. If they are just ugly about it, then that is when I would say, "It's either all of us or none of us!" But if they are kind of "eh" about it and look like they are willing to think about it, then I wouldn't say, "It's either all of us or none of us!" That might just rub them the wrong way.
Good luck!