I'm a new poster that's been lurking on this forum for a while now! It just so happens I can completely relate to your concerns regarding your cat and felt I couldn't just read and run on this one. I hope my own experience might be of some help to you. Apologies for the long post.
My cat was attacked and badly injured by a dog over 2 years ago now. He suffered severe nerve damage resulting in paralysis of his back legs and tail. The first week or so he almost constantly dribbled bloody urine and didn't defecate at all until about day 5. I created a bed of towels (regularly changed!) for him to lie in and I kept him as clean as I could with a daily bath (using a shallow tray with warm water and a safe anti-bacterial soap, I would carefully pull him into it and then wash his back end and legs, it was important to keep movement to a minimum).
Living in Egypt my options were limited in terms of vet care and hospitalisation, but I was advised to give him daily injections of steroids and and anti-inflammatory medicine (orally). Other than that, it was just crate rest and a case of wait and see. He gradually gained control of his bladder (the anal tract was never a problem) but this was over a period of months and sometimes I would despair if he would ever improve. Unfortunately nerve damage takes ages to heal, but if you're prepared to give it the time you can see some amazing results.
Today Harry gets himself around by using his front legs only. He's actually got a significant amount of feeling back in both of his back legs and tail, but because I was a bit slack with physiotherapy in the early days he's "forgotten" how to walk. I'm currently trying to remedy that and still hope that, one day, he'll be able to use all 4 legs again. For the most part he uses his litter trays (large tubs with a door cut out on one side so he can get in and out) but sometimes doesn't quite make it. He's happy and well loved, and there's absolutely no issue with his quality of life.
I turned to the internet and did a lot of research on feline (and canine) nerve damage, prognosis etc. If you haven't already found it, there's an excellent website called handicappedpet.net with an active forum that includes plenty of inspirational stories and advice. There's also a facebook group (members only) called "cats with paralysis and mobility challenges" worth joining.
I wish you lots of luck with whatever you decide to do. Acupuncture is definitely something I would have considered if I lived in a country where it is available. Electrical muscle stimulation and hydrotherapy (even for cats!) also comes highly recommended.