Okay, it just sounds like he met this new girl, is not dating her yet, but wants to. You two were only dating for a few months, anything can happen over a few months. He may have fallen out of love with you. Relationship are very peculiar. You both probably are very young and inexperienced in relationships.
He may still be in love with you, but confused about this other girl. Give him some time. He will make up his mind eventually. He will either choose you or this other girl.
If he made you cry that much over the past few days, you really should ask yourself if it is really worth it. Maybe you should try to find some other guys. There are plenty of fish in the sea. If he wants to date someone else, then there is nothing you can do about it.
The main thing is that you really need to decide if you love him or not. If he really hurt you that much, then why bother and wait for him? I bet that plenty of guys want to date you, but just haven't asked yet. Is it really worth the trouble of waiting for him? Maybe you should think about that for a while and then make your decision.
Either way, I am sure that things will work out for you and that you will be happy. Relationships may be confusing and frustrating, but it usually works out in the end.
-Chris-