17 yr old Stage 3 Kidney Disease

My 17 year old shihpoo was diagnosed with kidney disease with a 2.1 test result placing him just inside of stage 3 and a week before a grade 2-3 heart murmur neither of which popped other than a slightly higher creatine level within the last 6 months. He also has early stages liver disease that has been controlled with denamirin.

Has been refusing food mostly for the last week since the event that triggered the visits resulting in diagnosis. As of last night I have gotten him to eat 2 meals of boiled chicken and rice as advised after he largely refused the Hills canned that she suggested.

Current regimine of medications: -100ml daily subcutaneous saline that has slowed absorption since he has been drinking a bit more -3.75mg Mirtazapine/24hr -4.5mg Pimobindan/ split every 12 hr -250mg metronidazole/ split every 12 hr

I was advised to discontinue the Denamirin, gabapentin, fueosimide (20mg/12 hr), Glucosamine chews, and veterinary fish oil he had been on due to difficulty getting him to take the pill pocket, upset stomach/vomiting that had occurred.

My vet told me that we've got about 6 months left together and I just want to know how accurate that is likely to be and if there is literally anything else I can do to extend his life or improve kidney function?

I can locate the bloodwork and share that if it would be helpful at all.