Lyric discussion by mandolin 

A song about recognizing mistakes you have made; regret for things you have done; feelings of worthlessness.

Although it says there is no regret, I believe it's quite contrary: there is plenty of regret. Often, people try to remedy the after-effect of bad decisions by claiming that they regret nothing. This is often just a farce.

The said female has been throwing herself into reckless situations in the hopes of finding herself and finding meaning. But some of the things she does is ironic to this, such as meaningless sex. Already in a relationship with another, she is suffering feelings of confusion and something is missing in her current relationship. So she essentially cheats, and in the aftermath, is coming to the realization that there is no turning back once it's done. She recognizes the fact that she has done the worst thing she could to her boyfriend/husband: she has breached the assumed promise of faithfulness by committing adultery.

And so she remains. Her boyfriend/husband is awake, waiting for her, and probably coming to realize what she may be doing. She fears that she will encounter conflict with him, scared he will find out somehow. "What have you done?" is the eternal question that she is being plagued by. She has no idea what came over her, why she took such a drastic step and probably realizes there really wasn't anything missing in her relationship afterall--she was just being insecure. So now she feels that she has ruined a good thing, and is completely lacking in pride.

In the end, she knows it's going to bite her in the ass.

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