I'm sorry. You did everything you could. Sometimes it's sadly just not meant to be. Keep trying with the other one. I hope it all works out, I know how hard it is to lose a beloved pet. I wish you good luck from here on out.
It's a good sign that they're trying to hold on. Just keep encouraging them to eat and drink and keep an eye on their bums so they don't get infected. If you need to rinse them off make sure to dry them really well. Blow dryers work great and most of mine actually seem to enjoy them.
You could try putting a little neosporin (without pain meds) or even a dab of honey on their bottom. It may not help, but I feel at this point if they're breathing heavy you have nothing to lose. Do you have bedding or a towel in the tub? (not trying to nit pick, but staying warm is very...