This IS reality. Your refusal to accept it doesn't change it. It only keeps you stuck in the same place.
You can do NOTHING to change your wife. Have you thought about how your kids probably worry about "how Dad's coping" with everything? They are probably, by now, accustomed to their mother's periodic meltdowns, suicide attempts, etc. My guess is that it would give them great joy to see at least ONE parent living a sane, peaceful life.
Haven't you done everything possible to help her? Has any of it ACTUALLY helped her?