Sorry for your loss Steve.
It's hard to understand the pain and sorrow losing a pet causes. I remember my boy Roscoe, whom i had during middle/high school, college, law school, and afterwards, and having to have him put down at 16 years old. I balled like a baby. Literally sobbing at the vets.
THE most painful thing i had to ever do. Thankfully, in your case, she went peacefully in her sleep.
Just know you made that little girls life very happy and enjoyable. That should serve you well going forward. And when you're ready, hit the shelters. Someone will be beyond grateful to see you.