Oh my gosh...I am sitting here bawling my eyes out, with tears just streaming down my face...
Sweetie, I am sooooo sooooo SORRY about Lilly. Honestly, I don't even know what to say because no matter what I DO say it isn't going to take away the hurt, the anger, and the pain. I know EXACTLY what you are feeling because I've been in your shoes. It is SO painful to lose a furbaby. SO PAINFUL. And the hurt it just so RAW.
I am so so so SORRY sweetie. PLEASE - you and your fiance don't blame yourself. I did that when we lost our Cocker Spaniel last year...and it made it all the more hard on me. IT ISN'T YOUR FAULT. You brought her into surgery because you were trying to do what was BEST for her - and SHE KNOWS THAT. You wouldn't of done it if you didn't care, and if you didn't think that the surgery was the best possible thing for her.
God Bless you and your fiance and of course sweet darling Lilly. R.I.P. little sweetheart
Again honey, I am soooo soooo sorry