Hi brainfog. 25 mg of Lamictal is a very small dose. I would be hesitant to judge its efficacy at such an early point. The average doses of Lamictal for people with bipolar disorder are more in the 100 to 400 mg range (see Lamotrigine Dosage Guide with Precautions - Drugs.com). Abandoning it at 25 mg could be an unfortunate action as Lamictal is generally a pretty side effect friendly moodstabilizer compared to others.

I hope you feel better soon!