I can relate to this sort of thing in the past. It was all good on the night, then you just loose the interest later. Not with the long, self-justifying texts though, that's a bit weird.

I'm not saying anything new here but just forget her, it's gone. You've been too inconsistent now, and any attempts you make at trying to pull it back round later will just come across as needy. As Jaz said, you fucked up when you didn't fuck her.

Now go and feel good about yourself.