If i was him i would rather you break up with me than be with me and not even want to be. Don't lead him on, tell him the truth. Yes it will hurt, but better sooner then later. And I am sure if you tell him the reason and how you can be with him in that way, then he will understand. If he loves you then yeah he'll be hurt. But better than lying to him right? If you see no future than tell him
You can't break up with someone without hurting them. Although for safety's sake you can meet them in a public place, a restaurant for example, where they are less likely to do something drastic. Be sure to come in seperate cars.
Good luck !