John, I am terribly sorry to hear such news. I'd like to say something though because I too have personal experience with what you're going through. I've been flying airplanes for 30+ years, it is my chosen career. Over those years I too have lost more friends than I care to count. As a result I've seriously thought several times about quitting... getting out altogether. To many faces that I see at night that are no longer there. I came the closest to getting out of aviation when (during the controller strike some years ago) ATC put my jet, and a 727 in the same spot, at the same time, going opposite directions... it was soooo close. Made USA today and "made" me think.
The bottom line is that no matter what we do, there's always a chance to buy the farm. All we can do is minimize the risks for ourselves and others and go on with life. Sure, I could quit flying and probably get killed by a bus and so could you. It's not always what "we" do in life that gets us, and we have no way of controlling it. To quit riding, to quit flying, to quit riding my horses, to quit doing that which makes us.. "us" is to die inside... very early.
I don't want to turn into someone else by not being me, by not doing my thing.... and you don't either. Just take a break and think about it, learn something from it, acknowledge it, and let it go. It's the only way.
So sorry to hear your news. Bob