Using Lamictal @150mg but still feel unable to focus or concentrate

Background: I had started using Klonopin for 'anxiety' about 8 years ago, taking .25 mg doses about once per week to help with 'weird head feelings'. I was diagnosed with Right Temporal Lobe epilepsy at the beginning of this year, and started on a rx of 150mg of Lamictal (titrated from 50 to 150) prescribed by my neurologist. I've still needed to take the klonopin to help 'even out' my brain functions, though. Since the klonopin can also cause withdrawal seizures, I've decided to get off of it. Something that I did about two weeks ago. Question: The momentary blackouts I was experiencing prior to Lamictal have stopped. But: My brain still feels like it's not working correctly. I have issues with racing thoughts, inability to focus, and memory recall issues. The biggest concern is that I'm easily distracted... which is a problem in my profession (programmer). I've read that a lot of people taking Lamictal experience a level of calmness and focus. The neurologist expressed surprise at my symptoms, but seemed unwilling to change my meds. He suggested asking my PCP for an anxiety medication that I could take daily. Contrasting with this is my brain behavior when taking the Klonopin... which seemed to calm things down significantly. It reminds me of how some people with ADHD describe taking Adderall. There's an increase in focus. My question is: How do you know when your epilepsy rx is working? How long does it typically take to see improvements?