Why do so many women/girls take on all the blame for messed up relationships? You may not be able to see it, because as you said, you're not very experienced with relationships. But here's what lots of experience over the years has taught me. If a guy spends more time with friends than he does you, or doesn't include you with his friends, he's not just not all that "in" to the relationship. You asked him a simple question and he responded defensively and in such a way as to to cause you to question yourself. Asking yourself, Am I wrong for wanting to talk to him on the phone? Am I being too needy? I find it funny that he accused you of using him for sex. Hmm. Also, calling you unemotional and cold?
While he's gone for the next two weeks, it might be a good time to do a serious examination of this relationship. Ask yourself some questions and be honest with your answers. What do you want in a relationship and is he giving that to you? What are your needs emotionally? Are the two of you on the same page in that area? Do you want a guy who likes to be with you and treats you like you're number one? If so, does he? Is he spending enough time with you? Does he keep his promises? I'm sure you could think of more questions to ask yourself. The point is, if he doesn't have these qualities now, he won't next month, next year, or ever. And don't make the mistake of thinking you can change things in this relationship. You can't change another person. You can only change yourself. Just remember, if you change yourself to conform to him, then you lose yourself and learn to hate yourself, and no one else will respect you either.
Decide what YOU want and go get it.