Hi
Can you see if you can arrange for either a Macmillan nurse or a counsellor to visit him to discuss his views?
I am sure after so much prodding and poking he is thoroughly fed up with medical matters, but maybe a bit of time may give him space to think clearly.
He is lucky to have your support. I hope you are both strong to support each other through whatever he decides. Ultimately it is his decision and whatever he decides, he needs to know you will be there, even if if breaks your heart. it’s breaking his too, but he will need to feel in control.
Good luck
You may want to post a separate thread for more replies.