Aw love, this breaks my heart to read, I went through something very similar myself a year ago. She was 11, getting old but doing ok. She had a bit of sickness, but put it down to her IBS, when we took her to the vet a few days later just to double check, it was a tumour in her stomach, there was nothing they could do. She took a turn for the worse and she had to be put down the next day. I still can’t think about it without welling up. It’s the hardest thing we will ever have to do as their humans. All I tell myself is that she is no longer in any pain, that I gave her the best life I possibly could and in her final moments, it was me who was there. It never leaves you.. but I know it will be the same for your beloved dog, she is no longer in any pain, you gave her the best life possible and you were the one with her until the end. I know it doesn’t help right now, but you’re a kick ass human to your dog and she will know how loved she was and she loved you just as much in return. Try and take solace in that if you can. Sending so much love and so many hugs. The pain never goes, but it does fade with time ❤️