Really unfair - caught between two loved ones

I just told my husband that he is being rude and unkind to our son and needs to stop. It went down like a ton of bricks, which I knew would be the case, but I need to speak up for my boy because he is not old enough to do it himself, and when hubby isn't well he does need firm boundaries around what is ok behaviour towards our kids.
I hate confrontation and feel shaky and sick. I really resent being put in this position and I wish my husband would manage his health more proactively so these things would not occur as much. He needs to go back to the doctor and I have recently realised that I will have to push him to do it. Feeling disappointed that once again he hasn't done it himself.
I'm glad I spoke up but I wish I didn't have to.