Girls: How do you deal with boyfriends that don't like to open up?

I'm a guy, and my girlfriend hates to open up to me. I know, sounds weird, it's usually the other way around, but not this time. The other day, we got into an argument and I explained so much to her and kind of poured my heart out, and she doesn't say anything. She just says "Sorry." It's REALLY annoying and ******* frustrating when you get that "Sorry." after pouring your heart out. I have no doubt that she cares about me, she really does. She likes me a lot, and I like her. But sometimes, I don't know why she doesn't open up. It really bothers me. And even though I'm dealing with a girl, how do YOU girls deal with your boyfriends? Or how do you cope with bs like this?