1) Read back through your entire text message history. Note the times he said something affirming. Consider the things you said that may have been off-putting upon a second or third read. Text your friends about how they would interpret his comment that he “doesn’t like a lot of girls.”
2) Google articles about post first date calls. Is it still three days? Is it longer or shorter if he kissed you after and said he’d call you soon?
3) Draft scenarios in your head. Make sure you boil your experience down to some kind of false dilemma: either he is a bad person who was playing you for attention or he is an overly picky asshole who will never be happy.
4) Stalk. Check his Facebook, Twitter, gChat status, Foursquare, LastFM, Instagram, etc ad nauseum. Does he seem too busy with work to call? Did he post a picture of himself and another girl? Has he been listening to romantic music?
5) Think about how pathetic you are.