I'm so very very sorry for your loss!
It's such a hard thing to make that decision, even knowing it's the right decision. And hole lasts for so long.
I will say that I lost my Rebel in March 2013 and while the hurt is still there, the pain isn't so sharp now that we've got a new baby in the house. Consider honoring his memory when you're ready for a new pup to love.
Hugs to you!