aw man this almost brought me to tears because i know exactly how you feel :( i'm so sorry to hear this
all i can say is that with time the pain will subside a bit (i won't say it will go away because I'm still waiting for that day heh)
and eventually you will be able to smile and think about the good happy memories without just thinking about this horrible day and the sad end
the most important thing is he lived a good life and was taken care of so well, and when you're ready you can open up your home to a new puppy :(
:(
sometimes i think that... well if my cat was still alive we wouldn't have my dog, and I LOVE my dog, so that's a happy thing..and i'm so happy that we rescued him - he would have died in the woods and sometimes i can't believe that someone threw away this beautiful dog - and then i get really sad because I stinkin loved that cat.. so then i feel guilty about how much I love the dog.. hehe.. so it's a little bit of a vicious cycle... but.. the pain does subside with time