Have you asked him what you can do to make it better? I would try writing him a letter, because you can look at what you're saying, and better see how you will appear to him. It would be easier to get your thoughts together. Also, it would help to try and be calm. I've ruined a lot of situations with guys by not being able to maintain my composure and think clearly and calmly. Hand him the letter in person and then walk away. Give him some time to think about what you've said and what he wants to say back. I hope that helped.