Maybe what you did was wrong. But . . . why is it unforgivable? Maybe he can't stop being mad immediately. Some things take time to blow over. So give it time.

You seem to have a problem expressing anger to him. So you had to wait, until he was out of the house, to take a fit on an inanimate object. Sounds to me like you are holding yourself up to an impossible standard. You are trying to be perfect, so you can "earn" his perfect fidelity. Some people are faithful in relationships, and some aren't. It may not have much to do with what you deserve, or earn. Ask yourself what it was that you really got angry with. Maybe, despite all your humble protestations about how he deserves for you to be so much better than you are . . . maybe you are mad that you can't feel a sense of control over him. I think there is more to this than meets the eye.

You think he has been doing you an honor by allowing unworthy you to be his girlfriend. If he is such a lofty character and so far above you and beyond what you are worthy of, then you are not going to feel secure . . . ever. You need to stop idealizing him into some kind of a demigod, or move on to find a more lowly guy who is at the level you see yourself at.

You seem to believe that you don't really deserve him. However, if you follow certain rules like:"Don't ever upset him about anything.", then you have a basis on which to expect fidelity. Either the guy digs you or he doesn't. Either he needs what you have to offer, or he doesn't. You don't seem to believe that he does. Instead, he is graciously condescending to do you the favor of being with you. So, of course, you feel insecure, and that makes you mad. So you destroy something important to him. It seems like you are punishing him because he failed to obliterate all your insecurities. Is that even possible?

You're still mad about past infidelities by other men. Those men did what they did because they were not the faithful type. Otherwise, they would have just broken up with you. Wasn't it something like 7 men who were unfaithful. That sounds like you chose men who do not value fidelity, then you get pissed that you can't control that aspect of their character. You can't use "being good" as a control technique. Something is driving your anger. Maybe this guy doesn't need you, as much as you need him. That could make you feel vulnerable and, hence, angry. Deep down, you may feel you are dating out of your league.

If he dumps you over this incident, then he doesn't really need you all that badly. If you can be that easily replaced by him, then you are going to be replaced sooner or later. In a relationship where you are the suppliant, insecurity will always rule your inner life. Were you the one who pushed the idea of living together? Something here isn't adding up.