First, you have to realize and accept that you can't ever go back to "the way we were". That period of your life is gone. Second, you have to want to set a new "norm" in order for it to happen, and take it one day at a time.
My wife had to go through those stages before she was willing to move on. Last August, after her pneumonia, she decided she wanted to get better and do what she could do (not dwell on what she couldn't do). She has been sewing a lot (a love of hers) and the work and goals in that area have sparked a new positiveness. She is even going to take training to be a caregiver to others with lung cancer, even though she does not know how long she will be around to do this! I think that's the kind of attitude you have to foster. Focus on something positive and work toward it.
Good luck. There are many cheerleaders on this board for you. Don