Hard to explain my condition to doctor

I have been diagnosed with bipolar type 2 and currently prescribed Lamictal 50mg and Sertraline 50mg. When the Lamictal dosage was increased to 50, I felt a slight difference compared to the previous dosage. However, what I feel is a dullness and lack of motivation to be productive. When I consulted again at the next meeting, I found it difficult to explain my current condition due to this dullness. Do you have any tips on what I should pay attention to during this phase?