It is difficult to know why you began to have symptoms after years of stability. It was very wise to see a doctor. You did the right thing. You did not mention what type of doctor he or she is, (i.e. psychiatrist, general practitioner, etc.) but you may want to consider a physician who specializes in the treatment of epilepsy perhaps in addition to your current treating physician. That type of physician would likely be a neurologist. It’s important to be evaluated by a neurologist because of your history of epilepsy. It further complicates your current situation and may be part of the problem.
The problem as I see it, with the limited information provided, may be that the mood stabilizer is ineffective. It’s important to understand that when attempting to find the right medication it can be and often is a long complicated process. Your doctor should be (and likely is) prescribing new medications to try and find the right one or right combination, that will decrease your symptoms. As difficult as it may be, it’s important to remain patient during the trial and error process that often characterizes the search for an effective psychiatric medication.
If you haven’t considered therapy, you should. Therapy could provide you with the tools to assist you in stabilizing your mood. Therapy is a recommended adjunct to medication for most psychiatric conditions. There are specific techniques that a therapist could teach you regarding mood stabilization. If therapy is not an option for you, I would recommend educating yourself about mood disorders. Many books have elaborate behavioral plans that are designed to increase mood stability. Common themes of those books often include: getting enough sleep, eating a healthy diet, maintaining a regular exercise routine, dedicated relaxation time, refraining from drug and alcohol use, decreasing life stress, and maintaining a support system.
I am unfamiliar with mental health services in your country but hopefully you are able to access a therapist or other mental health professional who can assist you. Do not hesitate to go to the hospital if you feel that you cannot control your behavior. I wish you well. Please take care and good luck.