I agree with Monk about the sexual prowess on one level, you have it or you don't, but if you don't it does not mean you can't learn. All people's experiences are different. Plus, it is totally possible that this guy is a bit immature, in more ways than sexually. Sexually, he is not in tune with is partner, otherwise he would have known what he was doing "to you" was not right, and in some way, uncomfortable, as you described it. To me, this is a sign of his own selfishness, which is a form of immaturity. Your pleasure should be most important, because a happy partner is a giving partner (ala Carl Marx). Also, his insistence on having a conversation via text, sounds like he "could not wait", and belies his own words that "he is a big boy" and can take it, when his anger belies that he can't take it, another sign of immaturity.
Finally, the last sign of immaturity, is that after this Text Discussion, if he really felt for you and wanted the relationship to work he should have told you that texting was in fact the wrong medium for such a discussion, apologize for his anger, and asked you to meet him to discuss this in person, so he could get a better understanding of what you were saying, and maybe learn something about himself.
To me, you are better off without this childishness, and should find yourself a real man.
Good luck.
Tab