I'm so sorry about what you and Jack are going through. I'm praying that the oxygen will help him and that you receive some uplifting news this afternoon. Try not to be so hard on yourself, you could not have known that the vet wasn't going to everything he could for Jack. I would have assumed that a vet in practice, no matter what practice, would do their best and it is just awful that he did not. It's not your fault. I hope you'll be kind to yourself and give Sunny a hug. You guys need each other right now.