I dont think there is a specific disorder because really his behavior is a symptom of many different ones. But at the root of his behavior is a refusal to accept change in his life. He still wants to view Sarah Lynn as a little girl who depends on him because he cant accept that that period of his life is over.

I didn’t read the body of this so my first thought was “oh, you mean the thing Dr. Hu was prescribing the pills for? Uptight Dickhead Disease?”