Cat saliva is deadly to birds. (Pasteurella) It needs a vet and antibiotics, and now.
I'd call your local vet at your first convenience (if it makes it that long), and ask them if you can bring it in and drop it off, or if they can put you in touch with a local wildlife rehabber. You may want to keep it and I certainly understand the drive to make the injured whole again, but unless you're licensed or working under the umbrella of a licensed rehabber you're breaking the law.
I rehabbed raptors for a couple years, and my heart goes out to you. They can go downhill SO fast without the meds and supportive care.