Just reading your posts brings back my own memories of loss. It is going to be a difficult couple of weeks but remember that you cannot linger in the past. You cannot change the past. Don't beat yourself up or think about what you should have done differently. It's the past now and you cannot change it no matter how badly you feel about it.
She is not suffering now and although this was sudden I'm sure you gave her a very good life and she appreciated every second of it. I think she would be sad if she knew how awful you are feeling now. You have to have time to mourn your loss. Just don't beat yourself up about this. Sometimes circumstances seem to line up against us and we have no control over them.
We all have to keep moving forward or we will be stuck in a pit of regret and despair. I can start to cry just by looking at pictures of my past pets but I can't let myself stay there. Our pets are so smart in that they live for today. Your other pets must be a great comfort to you. I'm glad you have a supportive husband there for you,too.