My Satan kitty (aka Gracie) has had kidney disease for about 3 years. She is 7 (?) yrs old now. So its been an ongoing issue for quite some time. She was originally on a dry food only diet before I knew how bad it was. She then went to canned food diet...usually Wellness or Solid Gold. This went on for a brief time, maybe 6 months of her eating and maintaining her weight pretty well.
She went on a hunger strike about a year ago. Dropped from 15 lbs down to 6-7 lbs.

This went on for around 2 months, and I tried every concievable food for her to eat (raw chicken, cooked chicken, canned tuna, raw fish/cooked fish, cheese, etc). I finally said "enough" and made an appt to put her to sleep 2 days later. During that 2 days, I bought some cans of Fancy Feast to get her through. She loved it.....gobbled up 2 cans a day and started looking better.

I've tried numerous times to slowly get her back to a good food (mix in a tiny amount with each feeding) but it never works.
Now that she's finally back up to a 9 lbs (decent weight, but still a bit skinny)...she's decided that she no longer wants Fancy feast either. She started getting really skinny again, so I broke down and bought her some dry food (orijen) to mix in. She ignores the wet food and picks out the dry to eat.
Is it worth trying to get her back onto just canned food? Last time it almost killed her, and I'm not sure if she/I can handle it again. She drinks an absurd amount of water. Last time I measured her intake it was around at least 30 oz. Her last set of labs showed that her kidneys were worsening.
Any advice, or even just words of encouragement?