This is extremely weird - the combination of extreme paranoia and wit/humor. Maybe indeed he is a rare gem and you are right that you have a unique attraction to him on the strength of his personality.

Have you ever expressed a desire to see him on a more regular, predictable basis? I mean, if he cannot be emotionally available due to being severely and profoundly messed up, could he at least be physically available with some reassuring frequency?..

Just an idea.