Hi. This is so very hard. First, can I let you know about our very special User Group ... the CHRONIC KIDNEY FAILURE IN DOGS User Group on MedHelp. Please search for it, then join, and read through some of the posts there. Post your own message and people will respond (including me). Maybe just for support, but also maybe with suggestions. These are all owners going through or who have already gone through the same process with their dogs, so you will be made very welcome there.
Next, I have a couple of articles (written by me) that I would like you to read. They will help you become more informed - or maybe just confirm what you may already be thinking, but either way, they may help.
http://www.infobarrel.com/How_Diet_Affects_Dogs_with_Chronic_Kidney_Disease
http://www.infobarrel.com/When_a_Pet_Dog_Dies
Finally, have you got your dog's blood results. If so, please check what the results say by taking a look at this reference guide (again, written by me):
http://www.medhelp.org/health_pages/Pets/Canine-Blood-Chemistry-Results-Reference-Guide/show/1296?cid=3
Has your dog had any IV fluids? Sometimes, even in dire circumstances, this can help bring bad blood levels down. I must add, this doesn't always work, particularly if the kidneys are very badly damaged - but it can sometimes work wonders and give both you and your dog extra time. That extra time may also provide some leeway to start a management plan, which may extend the time even more. But this is a difficult journey ... and you are certainly not alone in it.
Tony