You may find some advice and help here:
http://www.medhelp.org/groups/chronic_kidney_failure_in_dogs
This group was started in 2014, and I am not sure how active it still is, but there are bound to be lots of posts there which you might get tips from.
I personally am not experienced enought with kidney failure to offer you the help you need. My own dog WAS diagnosed with very early stage kidney failure back in 2011, but she was showing hardly any symptoms and so our journey through that was quite easy. Her blood results improved greatly with the kidney diet plus Benazadryl tablets (ACE inhibitors), In only 2 months her values came back to upper normal. But she was a different case, a very early-stage case, and never showed any symptoms of kidney issues.
She passed away the next year from something entirely unrelated.
So that is my only experience you see.
I don't know how difficult this next idea of mine will be for you, but it is an idea if you can, to speak to a veterinary nutritionist.
In my dog's case I was lucky to find a contact number for one, and had a telephone consultation with her. She was very helpful.
Try not to be afraid of the subcutaneous fluid injections. I do know someone who has been giving their cat these sub q's for a very long time (at least 2 years!), and the cat is still going strong. Of course it may not last forever, but their cat is still enjoying life.
One thing you can try to do for your girl is remain as calm as you can with her. Be reassuring and gentle and loving but try not to panic or be afraid. She will sense that and it might make her nervous. Try if you can, to be as upbeat as possible, yet calm for her. I know that can be hard to do sometimes when you are so worried....but try your best.