My friend, I'm deeply sorry for this. Words fail me and my heart aches for you and your family.
My thoughts and prayers are with you and your sons.
I must say it now....
This is NOT your fault!
She was in pain and YOU were not the reason for this.
This is NOT on you brother it is not!
You stood for your M
You stood for your wife
You stood for your sons
You loved her
And
You did ALL you could
I can't imagine the pain you are in, it is far worst than I can ever fathom, but her decision to do this is not yours and there was nothing you could have done no matter what anyone tells you.
You are in my prayers, my thoughts, my heart
I am proud to have known you if only through this site.