Welcome to YT!
I am so glad that your vet knew that just the manufacturer of the drug was the issue and had you change. It's wonderful to hear that you have seen such an improvement over the past month and a half.
Have you tried to put the pill into a little cream cheese? I found this works the very best because the dairy covers the taste of the pills and it seems to always go right down with mine.
Anything else that I have ever tried to hide the pill in they would always spit the pill out. Good luck and I hope that this trick will help you with Kissy too.