Not your fault mate,you learn to compartmentalise death after a while,its something we are all going to face one day,but this ladies ill health isnt directly attributable to you,I paid for someones treatment when I lived in Pinas,it extended their life by six months,I would have paid every penny I had if it had meant even another week,sometimes we have to realise its natures way to be honest,just be there for your wife when she needs your support.