Dear Teddy,
What an appalling situation! But, please, it might be the illness talking, not your husband expressing a long-standing hate for you. After all, why should he have stayed with you, if he hates you.
I know you are a nurse, but it can still be difficult to realise that your spouse is ill and that the illness is causing his changed behaviour. My father was a G.P. but surprised me by not realizing some of the implications during my mother's last illness.
But you are his wife, so in your place, I would start by asking for a private interview with your husband's G.P. and consultant. After all your husband is telling you there is nothing wrong, while the hospital has informed you both that he has a carcinoma in his lung. So did my sister, but she died of an inoperable brain carcinoma, and it did change her personality.
Is the house in your name, or his, or in your joint names?
the other respondents seem mainly to be advising divorce, but if you like a small minority, myself included, still believe that in sickness and in health meant precisely that in our wedding vows, then that won't be an option, but do look into practical things like getting help to care for your husband, whether you will be entitled to a widow's pension, consider a POA if your husband's mental state deteriorates. I know al this is hard to face, but knowing precisely where you stand will, I hope, give you some peace of mind.
Keep us posted, please.