So Sorry you are going through this.

Sorry you had cancer in both breasts.

I had a quick google and chemo chan affect mood.

There are different types of chemo, his may be mood altering, not to mention he may be covering up fears of stage 4 cancer. 

It's good that you have come on here for suport.

No one likes to feel controlled or abused.

Ask yourself what was he like before the cancer, he may not be as well emotionally equipped as you in dealing with it.

He may have unprocessed childhood trauma that he is in denial about.

There may be lots of reasons. 

i am autistic so i am not good at suggesting what to say to him.

Be the bigger person, don't be controled but treat him with respect as we all like respect. 

Keep posting on here, you are obviously worried as he is your husband and he has stage 4 cancer.