He said he has slept well ever since. Putting yourself into whatever place was usually occupied by your loved one helps fill a painfully vacant space at those times of day or evening when you least want to be reminded of your loss. Sit in it yourself. For an indeterminate time, your consciousness will be filled with thoughts of the person you have lost. Eventually, as you begin to turn to other things, you may feel a sense of disloyalty, a reluctance to let your loved one go.
Life does go on under quite different circumstances.
It is the process of getting out of yourself. The most beneficial way to do this is not through purely social contacts, which are very important, but in doing something for others. Make a call on those in trouble, do errands for someone who is incapacitated, take part in some group or organization that matters. What you need so badly at this time is a diversion from your grief, a boost to your self-esteem, a substitute for emptiness. Doing something for someone else has twice the benefit of doing it for yourself.