Hi Sunny, I'd like to help you with your question.
I think you are correct in assuming that this man may have a personality disorder. Whenever someone is controlling and dismissive of your feelings, even if it is just sometimes, it can mean they have a personality disorder.
Although it is hard to tell without talking to this person face to face, my guess would be that you are dealing with someone who at least has traits of narcissism. The controlling and the self centeredness are characteristics of narcissism. Here is a description of narcissism. Take a look at the symptoms to see if it fits your friend:
Another personality disorder he may have traits of Borderline personality disorder. People who play games with other people's feelings and have rapid fluctuating emotions may have this disorder. Here is a link to help you:
It also sounds like your friend has some fears. It could be that he is so protective of his personal life because he wants control, but he could also be fearful of getting hurt or he could have phobias. Being fearful of being alone and of the dark are both indications that he has signs of phobias but it is not for certain.
Your friend can have more than one disorder at a time. People can have a problem such as a phobia and also have a personality disorder with it.
If your friend does have a personality disorder, it may be something you need to adjust to if you choose to continue the relationship. Personalities disorders can be helped through therapy, but one, the person must see they have a problem and want help, and two, personality disorders are not easy to treat in therapy. They can be treated, it just takes a while to do so because of the insight needed by the person and the altering of their personality.
The best option for you is to learn what you can about your friend and the options you have for responding to his issues. Here is a helpful resource:
Once you know what you are dealing with, it will be easier to cope and know how to respond.
I hope this has helped you,