I wish I had words of encouragement. What you described is exactly my husband. For 20 years since I met him, he exhibited odd behavior, zero executive function, cognitive deficits and arrogance and ODD through the roof. After I nearly had a nervous breakdown five years ago, he had some psych testing: extreme ADHD and NPD. However, with his 4 PANDAS kids ( 2 from a previous marriage), I had him tested for Lyme. Lit up like a xmas tree. Also PANDAS.
His whole life is one drama to the next, yet he sees it all as something being done to HIM, while anyone he comes into contact with suffers.
He is being treated for everything, but unfortunately with treatment for Lyme, Pandas, etc., those symtpoms have gotten better, and he regularly goes to therapy, but the NPD (arrogance, self focus, lack of empathy, etc.) Is increasing in leaps and bounds.