You're saying that your wife's physical appearance has changed and so you no longer desire her, so across the board say you had an accident, something happened to your face, or body she has the right to leave you or take an escort right, all things being equal, and you would understand because you only live once as you say. Yes I understand your situation, and I think you do as well. What if the new person changes in appearance, will you keep moving every time your attraction changes; if this is the case do you see any challenges in your life arising out of this circumstance?
Looks like you've already made up your mind and taken your decisions. How do you feel reading this back to yourself, what if she left you because you gained weight, as yourself honestly. I would say take up the challenge of being a hero and being mature to be a great father and loving husband, but the it's up to you, there is a price to pay for everything.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.