Treatment of epilepsy. What should i do?

My 19 year old son is undergoing treatment for seizure. Previously he was taking Levera 500 mg tablet. Now since last 8 months neurologist prescribed him Brivazen 75 mg. Since then i feel like a lots of behavior changes are happening in him. Aggression, mood swings, anxiety, depression and is not able to concentrate in any work. Are the side effects of Brivazen worse than Levera? Doctor has said that this medicine will last 3 years. I told the doctor about all these symptoms but he did not consider such side effects. He believe that these side effects are not there but i am feeling like this because of Brivazen. Should we switch from Brivazen to Levera again? Please help me and suggest what should i do?