Hello MM - I do feel you are in a v hard situation, an I know it can't be easy.
I think we have discussed before whether you might be depressed..and this might still be an avenue woth exploring.
I also DO NOT think your DH is a saint! He is doing exactly what he should do while you are out of action, with regards caring for your ds etc, but it does sound as if he is not comfortable around vulnerability and not good at dealing with it.
BUT the reason i have been quite upfront in talking about the things which you could do to control this situation is certainly not to have a go at you, but to give a glimpse of a possible way out of this longstanding, cyclical and worsening pattern.
No, he shouldn't shout at you when you are ill and in pain - but neither should you " ppush him a bit when i'm ill, to see if he'll still be nice to me.". And given that he clearly just is not good at talking thorugh things like illness and pain, it is fruitless and self-defeating to bring it all up again last night after he had apologised. First you say you think he has been readiong this because he is shouting again - then you admit that you brought it all up again after he had apologised...
I wish more than anything that you felt stronger physically, and emotionally - but in all truth I think it is YOU who can make yourself feel better emotionally right at this moment, not your DH.
In the longer term, you MIGHT be able to discuss this together in counselling, but left to your own devices the two of you seem to make it worse each time! that's the sad truth...You need your strength now to recover...so concentrate on that rather than trying to make your DH be supportib=ve in the way you want - you are on a wild gooe chase until you both find a new way to talk to each other....so leave that fo now, and just let him do the practical things - he sems to be coping with that side well enough.
I hope your consultant can give you some re-asurance about the op.
I really do wish you well - and better times than this, MM.