Oh dear, I am so sorry Yogi, if it is any consolation, I kind of know what you are going through, back in 2007, my Grandma passed too, she was just how you described yours, but she was only 68, and was taken before her time because of too large of an amount of anesthesia during a knee replacement surgery.
I was quite despondent for a while, but, I realized that she is in a better place, and that, things, will eventually get better; and Yogi I am sure that you will notice the same thing

Rest in Peace, Nana Yogi