Im so sorry to hear about your boy.
I have a friend who went through a torn tendon. She used him as jumper, one day he tripped and tore it pretty bad. Also caused her to crack her skull and need 6 staples in her head.
He was in resting for about a year. (She also had a baby during that time, which gave her horse extra time.) She has now come back to use him for dressage. He can walk, trot, canter and act like a normal horse now. He's still a beautiful mover. No more jumping though.
Wish you two the best of luck!