When the guy you're dating doesn't email you for days???

I'm dating a guy and whenever we are together he acts like he is crazy about me. He doesn't want me leave, he breaks other plans to be with me all the time, he even drove 200 miles to come to my house, and whenever I email him he responds within a few hours. But if I don't email him it seems like he would never email me! Like 3 days might go by and then I can't stand it any more so I email him. Does this mean he's not into me?? Should I just wait and let him be the one to email me no matter how long it takes? I want to give him space but the anticipation is so hard to take. What do you think? Thanks!!!