My dear girl of around 15 years just went. I don't have any memories without her. I love her so much. I'm not sure I will make it. Last year around this time I lost my grandmother (raised me so I call her mom) due to family legally kidnapping her and sold her home while also evicting me. And now I lose the only thing I had left that I cared about. I had to sign the papers. I killed her. My mom didn't even get to be there. Only via the phone.
Update: I can't stop crying. I can't stop hyperventilating. I haven't ate or drank in over 24 hours now. What if she would have been fine. What if it was just a minor set back. What if she thinks I killed her over the first inconvenience. Why did i do it. I killed her. Why. She is my everything. How can I eat when she can't. How can I get sleep when she can't. How can I be happy without her.
You made sure that dog had a wonderful and long life. This period is going to be incredibly rough, but don't blame yourself please.
Personal, but my little baby is getting up there in age. I'm going to immediately look into adopting another as soon as she needs to go. It'll be very hard to feel sad or depressed with another little buddy hanging out with you and keeping your attention. That might not be right for you, but worth considering.
Not to minimize how tough it will be, but it will pass. Take care.