Frankly, *I* can't even understand you. If you speak anything like you write, no wonder the guy gets mad. I really am not getting off on being a jack @ss here like most people online are when they write stuff like what I just did--I'm serious.
Second, while it's true that this is not necessarily a blanket indication that men don't understand women, I think that's a fair generalization. Most women are hard to understand, and I say that as a female--I usually don't understand women, either, oftentimes because women are not very straightforward about their thoughts/feelings and expect people to read their minds or signals.
If your boyfriend has a problem understanding you, it's either the way you communicate with him; he's one of those guys who doesn't listen to women, especially when they get upset; or both. If it's the former, then it's up to you to be clear when you're upset about what's bothering you and not come at him as attacking him but just very calmly but clearly. If it's that he doesn't want to hear anything you have to say when there's a problem, then you can't do anything about that except maybe let him know how you feel about his not listening and then kicking him to the curb if he can't correct that problem.