Bless your heart! Cancer brings out the best in people, but it also brings out the very worst. I'm still stung by the hurtful actions of people I loved the most in the world.
I've researched and found my cancer experiences are common. The cancer diagnosis throws everyone off kilter and their reactions are seemingly unloving and out of character My ex-husband, and several family members congratulated me on being able to get nice new breasts! Excuse me! Stage 3 cancer, 18 rounds of chemotherapy and a back that looks like Frankenstein from reconstruction. I KNOW not so.
I've just got to throw in another bless your heart! That's the all purpose phrase in the South for behavior like your husband's. I would really rather say, "What an #€€ hole."