I keep going on first dates where the man holds my hand, says I'm beautiful, kisses me and asks to see me again but then disappears. I only text right after the date to say "thank you." WHY?

Sounds like you've met a lot of "shallow" men. Most men aren't like that and if they actually meant the things they said to you, you would be getting more calls for more dates. Just keep trying until you find a real man who knows how to treat a lady.