What a heartbreaking use of Orpheus and Eurydice's myth. I knew it only had one ending but I still tried to prolong it. I felt selfish, too.
I have a cat, and she's my best friend. I know I'll have to make that decision in real life one day and I don't know how I will be able to handle it. I'm so sorry you're going through the same thing.
Also, I loved the background music! Sounds timeless and melancholic.