The reason he keeps you hanging on like he does is because he knows that you are still waiting for him to make up his mind and this is why he may be dragging his feet a bit when it comes to making a decision about you and the relationship. There is an old saying that "no one needs the needy" and it applies itself well to broken relationships. Begging, clinging, and desperate behavior is much more likely to repel your ex rather than attract him. If he knows that you will be there waiting he will not make up his mind anytime soon so you have to put your foot down and not be so accessible to him this may be hard because you love him but you have to make him see that if he waits too long you may be gone forever and may move on, you see right now he has nothing to lose because you are still there. You have to make it so that you aren't always there to take his calls or aren't always there to meet with him when he wants to. As long as he knows you will be there to give him what he wants he will not work for it or make any major decision about the relationship because he is already getting what he wants from you.
Closing the doors of communication may seem counter productive to rebuilding a failed relationship, but it is one of the most important steps. There is a reason that things have made it to this point, and it is obvious that someone needs a break. Allowing time for reflection and thought is the best way to evaluate your relationship. It could be that some time away will remind him of how valuable your relationship was. If he is in constant contact with you he won't be able to miss you or remember the times you had that made your relationship special because he still has that in you now. Do not contact him unless he contacts you and even if he does contact you then don't always be accessible or don't always answer his calls even if you really want to talk to him you have to show him that you are willing to move on if things do not change. Concentrate more on your school work or work so that you are not constantly thinking about him or if he is going to call, hang out more with friends so that you aren't sitting home thinking about him maybe go to the movies or out to eat, or volunteer anything that keeps you busy and not thinking so much about him so that you will give him food thought that if he waits too long he may lose you.