Don't waste your time ruminating over what you did wrong or what you can do to get a person to act as you want him or her to act. All you can control is the amount of bullsh*t you accept in your life and how you react to it.
There was a time when I actually used to spend hours trying to figure out what a guy's flaky behaviors meant.
Because he has no intention of this developing into anything more than sex.
We'd have sex, we'd get closer, he'd disappear, I'd get confused, he'd come back, I'd let it go and repeat.
If someone isn't ready to let you in, it's not happening. I have pushed someone away who I truly had strong feelings for; I have also had the same done to me. This is not always the case, but in my experience, when you have sex with someone too quickly, all logic and judgment goes out the window.
You both get caught up in the excitement and the endorphins, and all of a sudden, you think you know someone because you've been "f*cking and texting" for three weeks straight. You just think you know the idea you've created of this person. And, it may make you think you have “so much in common,” or that you have a good sense of who this person is.