My father has changed after his stroke. How can we go about helping him with his memory issues?

My father had a stroke 6 wks ago, he has full mobility and remembers people but he is going back in time,hes delusional, hes says things hve happened that have not,he doesn't remember that his whole family has passed on so he relives it every day he ask where they are if we tell him the truth.My mother is not doing well with this and I have never experienced so much pain to see them like this and I know it could've been worse but please tell me how to live with this,my faith has become so strong and God has given me a lot of peace but I feel I need someone to tell me what to do for them and me,God Bless