I cannot tell you how often I have had a non-ADHD partner contact me and say something such as “I have a partner with ADHD who is also a narcissist.” Though your partner seems self-absorbed, it is likely not narcissism, and with the right approach it usually CAN be addressed within your relationship.
Do you think your ADHD partner is a narcissist? If so, you would not be alone - the question of narcissism comes up regularly - usually asked by non-ADHD partners who believe that their ADHD partner is unfeeling, selfish and self-centered. But while it's easy to label someone who comes across as self-centered as a narcissist, the truth may be a bit more complicated than that.