Persistent afib means afib that has continued uninterrupted for over a week, so you're not there yet.
If you've managed to control your afib with diet and lifestyle for 12 years, you've done a fantastic job. Few people get that much mileage. But afib is a progressive disease, so it's not surprising that the party appears to be coming to an end. Assuming this isn't just a one-off event, going forward you basically have three choices: 1) Keep the rate under control, remain on an anticoagulant, and "just live with it." 2) Take an antiarrhythmic drug such as flecainide, sotalol, or a half-dozen others. 3) Seek an ablation.
All three choices have their pros and cons. Is your doctor an electrophysiologist (EP)? An EP is a cardiologist who specializes in treating arrhythmias and the electrical conduction system of the heart, which is what afib is all about. An EP can prescribe the drugs you need if you choose that route, and advise you in general on how to proceed.
Don't choose the ablation option without talking to us more about that decision. If you go that route,
who does the ablation is of paramount importance.