I hear how upset you are.
There are two ways that you can handle this problem. The first would involve giving him the space he asks for. In many cases, the space diminishes anxiety and makes it possible for the person to reconnect at a later point. The problem, of course, is that the anxiety will rise up again and you will probably find yourself back at this same point once again.
For this reason, it would be better to see if you can get him to talk about his fears. Talking is the only permanent cure. If you decide to talk to him, make sure that he doesn't feel pressured, like you have an agenda to change his mind or twist his arm.
Instead, he needs to feel that you want to understand him. To do this, say, 'I want you to understand that I'm not interested in pressuring you. If you feel that it's best for you to end the relationship, then I respect how you feel. All I would like is for us to understand more about what prompted this change of heart.'
You can go on to say that you have the sense that he is afraid of how close you've become. Ask him if it's true. If he says it is, then explain to him that acting on his fear by withdrawing or taking distance from you will ease his fear in the short run, but it won't solve his problem.
He'll never be able to have a lasting relationship with you or anyone else until he stops running and faces he faces this problem head on. You might then tell him that fear of intimacy is always due to two possible deeper fears: the first underlying fear is the terror of loving and losing through death or abandonment.
This fear is usually the result of having lived through a previous loss; the second underlying fear is the terror of being smothered, taken over, wiped out or controlled. This fear is usually caused by having been raised by an overly intrusive or controlling parent.
If he's willing to take a closer look at himself and work on resolving his issue, then I would suggest that he do my Personality Profile. It will identify the exact cause of his fear of intimacy and guide him on how to heal the problem. When the wound is healed, he won't need to escape from you any more.
Let me know what happens.