I have 4 dogs in my life until I decided not to take in anymore. The first one is a wild puppy who simply walked into my door when the gate is open, asking for food innocently, even though she can't speak. It is an abandoned dog as it is a female, nobody wants female for a pet here, all prefer male. Eventually most of my dogs come in wild and abandoned. Parting with my last one is the most difficult. Unlike the others who have lived quite a long life, she die early, yours remind me about that, the same, problems with her uterus.
Parting with your pet always come difficult. You are a first timer, I have already dealt with it 4 times. It is a very long time since my dogs died, but the memory will never fade away. It is not possible to fade away, after those days of having the most honest, loyal and sincere animal in the world as my companions, the impression is printed in my head that makes me feel a bit warm and a bit grief at the same time, every time I thought about them.
I always have a habit of taking pictures with my dogs, whenever I want to see their faces, I took out the album and look at them. The picture when they came as a puppy, when they grew up as an adult, and finally gets old. Parting is always the most difficult, there is nothing can be done, it is already expected it will happen one day, but the memory will never fade away. That's the best gift my dogs have given to me.
Hope you will find your way.