How should I apologize for this?
So I came on here about a month or so ago, asking for advice on my girl. Well things have been going up and down for us. I said a few wrong things and she didn't want to speak to me anymore, but somehow she forgave me, and we started talking again about 3 1/2 weeks ago. We actually became real close, and even though she was talking to another guy and actually started liking him, she told me the other day that not only am I one of her best friends, and she likes the genuine conversations we have been having, she told me we are getting closer together and she actually thinks we will get back together soon, but things in her life are just so messed up right now. Well the day after that, we are talking, and she goes, Hey I haven't had sex since you, and I'm kind of horny so give me a bit to take care of myself. So I told her, give me some back, and she said OK. Well, little did I understand at the time, she meant time, not pictures... So I sent her some dirty pics, and waited for her to send some back... instead I get a text saying You know you can't send me stuff like that. And at first I thought she was being sarcastic because the whole time I thought she was meaning send her some pics, but then I realized my error. Now she says that other guy was right and I can't just be a friend, and she needs some time. I tried apologizing, many times, but to no avail. She doesn't want to talk to me, she's horrified that I did that, and all it was was a simple misunderstanding. I feel bad of course, but I really honestly thought that was what she meant.
How should I apologize to her? Give her time and space? She already said no matter how mad she gets at me, she can't not have me in her life, and I know what I did really was not good, and probably destroyed all progress I've made in the past 3 weeks. I know she will eventually come back and start talking to me, but how do I let her know how sorry and regretful I am for that incident?
