I went through that exact same thing with my Jakey..
First of all, I am so sorry for your loss, I know the pain you are going through. I went through the exact same thing with my Jakey. Jakey's ordeal only lasted just over 2 weeks before we had to help him to the bridge last night, he was 6 and a half.
The vet came to our house, as it would have been too difficult to get him to the vet's. My husband, my daughter and I were able to sit around Jakey in his bed, petting him, while he slipped peacefully away.
It feels like I will never shake the guilt that if I had of waited a bit longer he would have come around, it's killing me. That is actually how I came across this thread, I was still trying to find someone with a boxer that was showing the same symptoms..
Magic sounds like she was a beautiful lady.
Jakey was such a handsome gentleman, my angel, my best friend.