My thoughts are with you, Kayty....
I remember my Mom telling me a story about how she lamed up one of her first horses. Took it from the training barn for a trail riding competition, the mare spooked and got a branch right through one of her tendons. I don't know the details of what else happened, but it ended in her having to put the horse down.
I have been lucky in the sense of not having to really deal with putting horses down myself. The last one we had to do it with, I was still too young at age 11 to really understand. I just remember crying a lot but not understanding why I was crying; It's just that everyone else was, so I thought I should be too.
When the inevitable time comes when I will have to consider putting my old guy down, I don't know what I will do. The thought of losing him is enough to bring tears to my eyes just thinking about it, but I hope when the time does come I will be as brave as you to recognize when it is finally time to say "enough is enough."
Pssh.I didn't pick up the wrong lead
It's called a counter canter...
...A very advanced maneuver.