What just happen?

I went out with Kay last night. We were just going to hang out. You know...dinner, a walk, and then some talking. Well we did that. Then the conversation went back to the last night we had together.
And then she kissed me. I'm sure I don't have to tell you where it went after that.
The crazy part is...I'm confused on how I feel about what we did. Don't get me wrong, the sex was amazing but...I don't know. It was so different than what I expected. Granted, we are adults now and we both have had other experiences but it somehow threw me back. And I was afraid. Like her mother was going to walk in at any moment.
Like I was going to end up on the sidewalk, half naked and bleeding.
I couldn't relax. And she could tell.
She says that she would like us to have a second chance. And I feel like there is something wrong with me because I can't let go of that horrible scene with her mother and somehow, that is holding me back from being with her.
There is something wrong with me...isn't there.