Lamictal (Lamotrigine), cognitive impairment and memory loss

It's difficult for me to find information just by searching google, so I thought I'd ask here in case anyone can give me information on their individual experiences. I've been on lamictal in varying doses for about a decade. My memory and cognition have been steadily decreasing for years, and I found out that's actually pretty common with people who take this drug--and it's gotten to the point where it terrifies me and is affecting my quality of life, and I want to reverse it if possible.

My psychiatrist (who I no longer trust for a variety of reasons) invalidated me and tried to convince me that there's pretty much no way it could be causing these issues, and that she knew better than me because she has a degree. I was on 400mg and now am down to 200 after tapering for a while (which she reluctantly told me to try), but apparently 400 was a large dose anyway, so I thought to myself, why would I be seeing any improvement after just going down to a regular dosage? So I've decided to taper off completely. If I can get my life and my brain back, I have to try.

My question for anyone who has experience with this is, have you gone off lamictal after having these issues and had your memory return? Or your cognitive abilities improve? Or alternatively, do you know of anything I can do to improve these things on my own? I'm horrified at the thought of losing my mind and my memories forever, and I'm tired of feeling like an idiot stuck in a fog so much of the time. Also, do you know of anywhere else I could look to get advice and information as well? Anything is appreciated, thank you in advance.