i know how that feels
my dog died and he was the 1st pet i ever had
he was only about 5 or less hours older than me and he protected the house well
but he is a german shepard so his bones and stuff weren't that strong
the last few weeks he lived was paifull to watch
his legs were so week that he wasn't able to walk, he turned deph, his eyes were turning into a white and grey color and he threw-up every 10-20 minutes
so we decide to put an end to his misery this year and put him to sleep