Sorry for your loss. I know exactly what you're feelin. Last year we had to put my dog cocoa down. She was a irish setter/springer spaniel mix. The best dog i could ask for. We got her when i was 2 and put her down when i was 18. Needless to say i DIDN'T know life with out her. It was like putting down my little sister. Even now, over a year later, even with my new pup, i miss her.
Best wishes man