I'm sorry to hear about this, OP.
I have a DD an the autism spectrum, and although she is pretty high-functioning (asperger's), her diagnosis was (and still can be) difficult to come to terms with. We go through our daily lives, but we are continually reminded of the challenges. We have learned that we will have our ups and downs (and heck, everyone does on different levels), but we will try to get through them as best we can.
As far as your DH is concerned, I know it's hard for you, but please try to be aware that he is dealing with this on his own terms. Having support is important, but it doesn't sound like he can give you that right now. Perhaps, over time, things will change, but you may need to learn to rely on other family or friends when it comes to this particular issue.
I hope that you can get your billing issue resolved and I will cross my fingers for your little one. Hugs to you