Hi Marcia and thank you for your question. This is Dr Linda, a vet with 11 years of small animal clinical experience.
I am very sorry to hear about this diagnosis, it can be such an upsetting and frustrating condition to manage.
Firstly, we aim to control any itch as best as we can, as itch is so often a trigger. This means immaculate flea/mite prevention and treating any underlying allergies, as well as the use of anti itch medicine where needed. Steroids and imega 3 supplements can be useful for many.
We also want to regularly check for any source of pain such as a oral resorptive lesion in her mouth, an ear infection or anal gland disease.
Gabapentin is often something I trial too, but if it does not help, I'd consider alternative medicine; perhaps Fluoxetine or Clomipramine.
Other things that help some cats include e.g. acupuncture and physio; it really depends on the patient and can be quite trial and error.
Whether or not getting another cat is a sensible idea, is a big decision and really up to you. It is important to state that many cats prefer to be 'lone rangers'. If she is not used to licing with other cats, it is worth fostering first, to see how things go.