I'm sure there are other's out there who have experienced what you are going through. Anxiety CAN go into a remission for very long periods of time. Even though you say the divorce you're going through is "for the best," it's still a traumatic life change and could be the reason your anxiety has resurfaced.
That you have obviously sought treatment tells me you are aware of your feelings, which is a good thing. You don't say how long you've been on the Zoloft and Ativan, but apparently it worked for you in the past. Perhaps you've just not given it adequate time to get into your system? Maybe the dosage is different? These are questions I think you should discuss with your doctor.
Don't give up..............you'll be fine!
Peace
Greenlydia