Some people wear their emotions on their sleeves, but it sounds like you have them all over the place. One thing you should keep in mind is that, if it's only the first date, then the guy doesn't HAVE to respond afterwards. You're still a stranger to him and he's a stranger to you. Take your first dates with a grain of salt. Enjoy them, but don't build any feelings. If it was multiple dates and you became friends, that would be another story.
The frequent messages will only distance him further from you. One is enough. If someone wants to know you, trust me.. they will. It's clear he doesn't, so let it go.