My dog died

My dog died on Tuesday via euthanasia. I was there, I watched her as her head slowly fell to the ground and everything in her stopped. I feel really depressed and sad, but then I feel happy for a few hours because of other reasons. Is this normal? She was going to turn 13 in April, she was my best friend ever since I was 4. I feel like it’s impossible to love any dog the same way I loved her. How long until it hurts less?