OP,
It's very easy to sound concerned about others being ill when it doesn't impact you in the least.
Words mean nothing.
Actions count.
He chose to not give a damn about you when you were ill and was repeatedly defensive when you mentioned it.
I suspect you do everything for him, and he is just another selfish man who has shown you, with his actions, a big insight into his character.
It is well known in relationships, that you get a real glimpse of how deeply someone feels for you, when you are most weak and vulnerable.
He has shown you very clearly an insight into how he feels about you when YOU were sick.
You can get defensive about it, or you can reflect on this new knowledge.
He expects you to always be well and to always do everything.
Heaven forbid he is even slightly inconvenienced by you being very unwell.
By all means run around after him like the skivvy he clearly expects you to be, now that HE is ill.......very silly IMO.
But, I strongly suggest you don't get seriously ill.
He is not someone to depend on.
After 20 years together he couldn't find the kindness towards you, to step up and show his wife, and mother of his children, a bit of basic care and consideration when she was feeling awful.
Actions not words are what count in the real world.
Let this be a timely wake up call.
I hope you feel better soon.