It's emotionally unhealthy to hold onto your old pet for too long. Some people say it is selfish, the animal is suffering and they're probably right. It seems right to try everything, but you have to wonder for whose benefit all that is. Never again would I prolong it after being told and figuring it's over - and i've pulled out all the stops - maybe you need more time.

Not saying you need to let go tomorrow, but it seems it is coming very soon. So, wish you best of luck.