To add to the chorus. You did the right thing. You saved her from worse - if indeed you ended up married and cheating, you would've been a bastard. But you're not.
Now, as to the blame thing, there is no blame here. This is just a situation. You didn't betray her, though she may think that. But what you did do, and there was no hope of avoiding this really, is destroy her fairytale. She had in her mind an idea of you and her, and your white picket fence, and bouncing babies. Telling her that you're bi killed that.
It shouldn't, because hey, you're bi, and there's no reason why you two couldn't get married and have all that. Gay men can't go there, but Bi men can, and often do.
She's got to figure that out on her own. You can't do that for her. She probably thinks somewhere in her head that this means your gay. She may suspect that you were using her to hide the truth, she may think that you have a guy somewhere.
It would help if you could find a way to communicate to her that bi is not gay, and not on the road to gay (provided you are actually bi and not gay) That you do in fact love her.
I'm going to disagree with some of the others here a little bit. You should give her the opportunity to communicate now. Don't push, don't hound, but let her know in some way that you're open to talking. I think that whether she takes you up on it or not, it's important to let her know this is a priority for you. Silence "until she comes around," is a bad idea, she'll think you just don't care enough. Let her know you want to talk, then let her know she sets the terms, THEN let her be. Whenever I get into arguments with my guy, he's the first thing on the agenda, and he knows it.
If she has sense, she'll probably come to see that you respected her with your honesty, and respected your relationship because truly, she had a right to know.
If she ever comes around and takes you back is going to depend in large part on how much homophobia she's got in her head, and how open, and fair minded she is. If you chose well, you have a chance. If you're dating a right wing zealot, no chance.
Just to be clear, you DIDN'T cheat on her right?