How old are you Calranthe?
Are you young enough to allow time to heal things, and have a life again in the future?
If so, then this I hope would give some cause for optimism, as would not having someone you care about suffering and in pain. I'm sure to the layman this will sound sick, but I recently lost my father to cancer, and in the end I was actually grateful he passed so quickly, sparing him the agony and misery he was in.
I hope you can build a new life again, and make your wife proud. I hope things work out and you get the karma back for all the care and effort and dedication you gave for your wife.