A truly tragic tale, Mook. It was upsetting to read.
Although different circumstances I have some empathy. Several years ago my mother was diagnosed with Parkinson's Disease. To see someone you had been independent for all her life slowly succumb to that horrific disease until she died a little over three years ago was horrendous.
You can give all the platitudes in the world, and mostly they're true. Doesn't make it any easier to live through.
My thoughts are with you and yours.