You are a knight in shining armor for loving and caring for your wife! I just caught on to what has been happening to my husband for the last 4 years and I am petrified of the future. Recently he kept getting up to go to the bathroom and tried to pee in the closet or other doors when I realized he could not see his way to the bathroom so I got motion lights that stick to the walls/furniture and light his way then turn off. He has not gotten lost since. That may be simplistic for your wife and may not be the solution. She may need a sitter so you can get some rest. If you cannot afford one, finding a good home for her ( or assisted living for you both) may be the next step. Your physical and mental health may depend on such. It is OK for you to change your promise of caring for her at home!!!