Does carbamezepin worsen cognitive abilities?

Potentially. Carbamazepine has been associated with mild cognitive slowing and changes in memory in some patients. Discuss with your prescribing physician whether a medication such as Vimpat (lacosamide) or lamotrigine would be a reasonable option for you. Of additional concern because of your history is the possibility of obstructive sleep apnea--which can definitely lead to cognitive issues. Sleep testing?