Most Helpful Girl
She might be regretting having sex with you. There are a few things that could be going through her head (and I'll be completely honest):
•She regrets sex with you because you didn't treat her right after (this one I don't think is the case since you said good morning and treated her like normal).
•She regrets sex with you because she feels ashamed of her actions
•She regrets sex with you because she's crazy and you didn't do what she wanted you to so it's your fault
There are numbers of reasons, but you can tell where this is going. I'm honestly thinking that she is ashamed of her actions (not because she didn't want sex, but her reputation wise. no girl wants to look dirty).
As for what to do... I would be there for her. Ask her directly, comfort her that its okay, and focus your relationship. Make sure that she still feels emotionally attached with you as she did before you had sex. It'll be difficult, but you just need to go for it. It may be awkward, but if you don't do this, it will be even more awkward.