Your post was very clear; you did a good job of writing it out.
The symptoms that you are experiencing certainly sound like anxiety (GAD). Yes, it was probably not a good idea that you went off your Prozac, anti-depressant. I'm not certain how long you were on it, but the minimum length of time one should stay on an anti-depressant is one year. And of course it is best to talk with your doctor about discontinuing any medication, and if it is okay with your physician, one should slowly taper down the dose of any anti-depressant.
Unfortunately, anxiety disorders/panic attacks/depression are often times chronic conditions, Lewis, requiring continuous, lifelong treatment, no different than a diabetic who requires insulin to maintain their quality of health. Also, starting and stopping anti-depressants is not a good idea as they can lose their effectiveness over time.
Glad to hear that you are back on the Prozac. Give it time to work.
The very best to you, Lewis!... Chuck