Lamotrigine side effects

I was doing perfectly fine with my 300mg lamotrigine for 5 months but suddenly, in the last months, I’m having cognitive side effects. I forget certain words way more in the middle of sentences, started slightly stuttering and my recall of things I’ve read has become terrible. Which is so rough for me because all my life people have lauded me for my great memory. And the memory deficit is making it harder for me to do my research (STEM PhD student) because I can’t connect logical things like I used to. I’m guessing that my recent change in birth control might be the cause. Because I’m on a 3x lower dose of progesterone based birth control than when I started the lamotrigine. Progesterone causes anti convulsants to metabolize faster so I’m thinking that the levels in my blood are higher now and that’s what’s exacerbating this issue. I’m out of state for another month so I gotta wait to bring this up to my neurologist. Gah.