Kruncchyfrogg, I am truly sorry to hear of your loss. We had to have the scottish terrier I grew up with (and who was born 1 year to the day before me) put down when I was 17. He had a cancerous mass over his trachea, so he couldn't even lay down and go to sleep because the pressure from the mass prevented him from breathing. He used to sleep next to me every night, always ran the same laps around the house when I got home, and stayed by my side every second I was at home. Heck, the day before he died, he caught a cat in the back yard and pulled some hair off its tail- and he came back in looking very happy with himself.
I guess my point is that you said you lost your best friend today- but consider that to your dog, you were his best friend and more than you probably will every realize. You were everything to him, and it sounds like you gave him a happy, wonderful, safe life. I know that he'd have no regrets, and he'd try to do everything to help you that he could if the roles were reversed. When you were injured or sick, I'll bet he was right there with you, trying to figure out what he could do. Even though its hard, you did the right thing, because no one deserves to suffer. Be happy for him that he won't feel bad anymore, and remember the things he did that made you happy. I'm 29, and even 12 years later, I still kept some of Angus' old toys and his favorite pink towel to remind me of him. Maybe keep a few of his old toys, just to remember him by.