The guidelines for stopping antiepileptic medications, has been suggested by experts after they analysed reports and studies published in medical literature. Most neurologists would not start treatment after a single convulsion, if the EEG and MRI brain are normal and there is no family history of epilepsy. The consensus is emerging that a 2-3 year treatment period (with no fits during this period) may be adequate in selected cases of epilepsy. The fact that you had a solitary fit, took 2.6 years of treatment, and have not had a recurrence of fit is a very good sign, Do not worry about the 3 year period. A number of us would agree that stopping the treatment after 2.6 years was a good idea. A number of us would have stopped the treatment after a 2 year fit-free period in your case.
At present, our concern is regarding your depression and anxiety. First and foremost, remember that you have successfully been treated for fits and the medicine was withdrawn at the right time. Start exercising, develop a hobby, mix with friends, and understand that by worrying you are not going to change things. Meet your psychiatrist periodically and learn ways and methods, besides medicines of course, by which you can improve your coping skills and improve on your strengths. Good Luck.