I'm SO sorry to hear about your baby. I'm glad you are staying positive and realize that you did everything you could and provided the best care for the little one and it was completely out of your control.
Also, it's incredibly responsible of you to hold off on getting another baby to make sure that you are prepared in the case of an emergency with Sheba. Many of us would be tempted to run straight out and get another baby to oooh and aah over to make us feel better.
Please let us know when you get the results from the vet.
