"Lucky" you to have not had this lovely thing called anxiety until age 59
The good news is you likely don't have years of habits of worrying so your recovery should be fairly swift and complete. Are you seeing a therapist? I think you would really benefit from this as your anxiety was illness related, not just "out of the blue" like some of us.
Have you had your thyroid and vitamins/potassium etc tested lately? I'm wondering if your illness could have messed with things. Worth checking into if you haven't. Vitamin D3 deficiency is really common.