They think you dont like them. Believe it or not, but a lot of people are just shy, and they are afraid of being rejected. Your date might have gotten the impression that you dont like them. If they assume you arent interested, they wont text you to set up a second date.

Why hasnt he messaged after the date?

He may have just went through a bad breakup or is focussing his priorities elsewhere, like his career. Or maybe his intentions for dating were just awry from the get go. He may have been using you as a distraction for getting over his ex and didnt even notice.

What does it mean when a guy doesnt text you after hanging out?

The fact that theyre not texting you has nothing to do with you. Not getting that text you so badly want might mean theyre not ready to date, theyre too self-absorbed, or theyre emotionally unavailable. Its about them, not you. Dont let your value as a person hang on something as silly as a text.