Sorry Alex,
I waited 8 years since putting down my last one but the healing was done and we picked up a really nice German Shepherd puppy about a year ago.
This will be our third and probably our last. Kids are in college and we won't have the strength or energy for another puppy in 15 or 20 years.
Making the decision and following through with it, is one of the toughest things we face as pet owners. Stay strong, remember the good times, if he is in that much pain, he will be in a better place soon.
Your family will understand and grow from it. And time will heal your pain.
Good luck.