Sorry to hear about what you're going through. I'm sure my hubby feels the same way too at times. I know I've certainly put him through hell at times.
What I can share is that when I'm feeling really out of sorts, he makes sure that I'm in close contact with my doctors and sometimes even comes to my appointments just to give his side of how he see things in me. That's important.
Also he gently tries to encourage me to get out of the house or to just do things that he knows I really like. He knows during certain times socializing is really hard for me so he'll suggest something for us to do alone like going for a walk any maybe some ice-cream, going to the zoo or going out for dinner.
And yes...sometimes I just want to be left completely alone. But that should not be left to go on too long.
If it is really hard for you, want not try to get some therapy for yourself? You really deserve it. It may help. A lot of people that help care for others who have illnesses seek that out and it helps.
Wishing you all the best. Keep us posted on how his appt. goes and how your hangin on.