Most Helpful Guy
Yes you're over reacting. I'm not exactly sure what's bothering you... the fact that he's dating other girls? As long as he's still dating you then don't worry about it right now. After a few dates with him if he starts to like you more he stop seeing the other girls (or pick who he likes best).
Most Helpful Girl
You are obsessing over nothing. He told you he had fun, and that he wants to see you again. He kept communication going after the date. I think this is a best case scenario... It doesn't matter that he is seeing other people. It is healthy, and if you guys hit it off, he would stop seeing them.
I wouldn't text him, but wait for him to let you know when he would like to see you again. This is what he suggested anyway, and you agreed to. If he never texts you again, I would just put it down to him losing interest, and that's fine too... Just move on. Have a feeling he will be arranging a second date though... Just hang in there.