I am really really sorry I didn't respond earlier this week. You have so much going on, I wish I knew what to say other than I wish you had a break from the pain.
It makes me angry to read that the hospital staff was so cold and that your H's family was so demanding.
And having a sick pet!!! Oh, I know how hard that is. I had a diabetic older kitty and he was a money pit but I couldn't bear to lose him. I finally had to decide based on his quality of life, which was only going to worsen once he was diagnosed with heart disease.
Is your dog treatable? Sounds like he might be? Both Petsmart and Petco have charitable foundations--you may want to seek out info on that. Maybe someone can point you to the right organization that could offset your dog's health costs.
I am also mad at your T. You don't have to feel this way for the rest of your life. That is lazy and uncaring for her to say!!! Ever considered a new T, one that can offer a path to hope?
Take care

