Krazyaboutkatz,
Thank you for your reply. It is so nice to find people who've been through the same thing and who understand.
If it was only fighting, we may have continued to try things, but with the stress causing the discomfort of the cystitis for Tiger Lily, it just wasn't fair to keep trying because WE wanted to keep her with us.
I went through a lot of guilty feelings in my heart, even though my mind screamed at me that we did the right thing in re-homing Tiger Lily.

I do plan to post more regularly here now! Looking forward to becoming familiar with all the humans and kitties here!