If the joy has gone out of a thing that once brought you joy, that once was your passion, examine your thoughts.  What has changed?  You may blame the change on external factors, and most certainly those contribute to the change within you, but the only thing that causes change within you are your thoughts.  Do you wish to find the joy again?  Begin with your thoughts.  Perhaps it is time to move on to something else, or perhaps it is time to get back to the thoughts that led you to find the joy within in the first place.  Why did the thing that brought you joy bring you joy?  If it was because it brought you to a place of knowing your connection with the Divine, with your very higher Self, then the joy will still be there.  This does not mean you need carry on with this activity forever.  Simply know that the joy cannot go out of your life, for joy is the basis of all life, and that includes You.