He’s being clear with you that he doesn’t want a relationship, so you should take him seriously. You have no reason not to. That should be the beginning and the end of the discussion.
But you have another issue which is keeping you in relationships that aren’t right for you and that issue is a fear of being single. Until you accept that it’s better to be single than tying up your time with Mr. Wrong because he’s keeping you from finding or being found by Mr. Right, you’re going to have troubled relationships.
My suggestion is to stop seeing him since he isn’t offering you what you want, and make the decision to go for what you do want — Mr. Right! — even if it means being single until you find him. 😉