@Denise Brewer Hi and thank you for your question.
I'm Dr. Linda, a small animal vet with 10 years of clinical experience.
Let me start by saying, I am sorry your cat is experiencing these issues and know you will be concerned.
I'm not sure what you mean by 'the urine is acidic'. Does it smell strong or is it darker in colour than usual?
If her anal gland has an abscess, this can lead to pain and a fever. This could certainly cause a decreased appetite. If she has been grooming the area, we could see bad breath and drooling.
We can use a buster collar to prevent this.
I'd want to ensure this abscess has been treated effectively with e.g. antibiotics and anti inflammatories.
If signs persist, I'd advise a general blood check to assess for any underlying issues such as liver or kidney disease. I'd also consider an oral exam under sedation as I'd be suspicious of dental disease and we cannot always assess teeth well in an awake cat.