I am so sorry about this. His anger is not directed at you although it is so hard to see him that way ... he is going through his own grieving stages as well.
When my mom had her cancer, it was at this time of year as well. I remember we had to be so firm with her to eat and drink water and she hated it and would get very angry with us. She also was in a lot of pain, and I remember feeling quite powerless because we could not help no matter what we did. It is so hard and I am so sorry you are going through this stressful and awful time.