Yes, if you can see him as the sick, fragile human that he is and try to make your last visit a comfort to him, I think you will feel much better about yourself. He didn't do right by you, but you can still do right by him by not causing him more pain, and showing compassion for a dying man.
Nothing you can do now, it is in God's hands.
Forgiving him is an inside job anyway - it is for your health and well being.