Metacam!

Hi, my Feebie cat had what i was told was a bladder infection, she was perscribed metacam 0.5mg/ml oral suspension @ a daily dose of 2.3 for 5 days. She started to be more herself after the second day, and was eating/drinking fine. after day three she was not happy, but she did not seem more ill. She had gone off her water (but the vet said this could happen) but she was still eating her wet food. The forth day i had issues getting her to take her medicine so she only had about half of the dose as the rest missed her mouth. The next day i had to take her back to the vets, as her back legs started giving way and i found blood on the outside of her mouth and she would not let me open it.  I was then told by a different vet at the same surgery that she had renal failure, and had to be put to sleep. I have since read a lot a bad things about this drug and feel that it is responsible for the death of my poor baby girl! Should metacam have even been used for a bladder infection? And for 5 days? I hate myself for not looking into metacam before giving it to her, but i thought i could trust in my vet to be doing the right thing for Feebie. Any help or info on this situation will be much appricated. Thank you!