I'm sorry for your loss.
You made the right decision. I've never had to put a dog down, but I can imagine that there's always doubts about 'when' the right time is. I could see that most people would keep thinking "just one more vet visit/month/etc." but it was clear that your poor little dog was in pain from her conditions and spent more time suffering than being happy in the end--you did the right thing. I also think it is normal to feel relieved--you have been constantly worrying about her health and comfort, and now that worry is gone.
You made the right decision. I've never had to put a dog down, but I can imagine that there's always doubts about 'when' the right time is. I could see that most people would keep thinking "just one more vet visit/month/etc." but it was clear that your poor little dog was in pain from her conditions and spent more time suffering than being happy in the end--you did the right thing. I also think it is normal to feel relieved--you have been constantly worrying about her health and comfort, and now that worry is gone.