This is Dr. David
lamotrigine is a medication used to treat bipolar disorder which is a mental disorder with severe highs and manic episodes as well as causing severe lows and depressions.
25mg twice a day is a very low starting dose for this medication.
the dose has to be slowly increased up over time up to 100mg a day with a max dose of 200mg a day.
it doesn't sound like your doctor has started to slowly increase the dose properly.
does your doctor think you have bipoloar disorder?