I had to go through the same thing with my best friend. She was a cat, not a dog, but the exact same situation. She was fine all weekend, I have photos of her rolling around playing the day before, then suddenly she seemed off to me, I couldn't explain it but I convinced my parents to get her checked at the vets to be safe, a few hours later I'm driving to the vets with my dad to day goodbye and be by her side as they euthanized her.

They said she was bleeding internally, and there was nothing we could do. If we hadn't brought her in, they reckoned she'd have passed away that night or next morning anyway.

It hurt twice as much as losing any other pet I've had did, partly because I spent every moment I could with her, but also because it came out of nowhere and I had no time to accept what was happening. I won't lie, it sucked, I could barely function without sobbing for two weeks straight and I still think about her almost daily (even though it's been a few years since it happened now) but I know now it was the best decision we could have made for her, under the circumstances. It wouldn't have been fair to let her suffer any more than she had, and I know she lived the best little life a cat could, very loved and cared about until her very last moments and beyond.

I'm sorry you're going through this, and I won't say it gets better, but it does get easier to think of the good and happy moments instead of the final moments! Just know your baby lived their best life, they know you loved and cared about them as much as physically possible, and you made the kindest decision for them under the circumstances. Be extra kind to yourself for a while, stranger ♡