I have learned to not do that "lots of email/chatting" before meeting someone. I think you can develop a false emotional connection to someone by "filling in the holes". You may really like someone on the phone, yet not be attracted to them in person. It is also easy to "date" if you never have to meet, once you meet, then it becomes so much more "real". It sounds like he isn't ready to really date.
There are a million "reasons" why he may have poofed, but they all lead to one place...he poofed, right?
I have learned to meet fast, then watch behavior. I TRY to act like I am interested, but I always hold myself back. It may or may not hurt me, I don't know. But it is a hell of a lot easier to not get attached to someone and not have to deal with that feeling of rejection.
I JUST posted about a guy where I can't exactly tell what is going on, and although confused last night...today I've moved on. It just isn't worth what little emotional reserves I have to want something that may never happen.
It is very simple to me. I want a guy that wants me, as much as I want him. I'm going to know it when I stumble into him. The behavior will be right. I want to be adored and loved by the right guy (not just any guy), and if I never meet him, I'm perfectly good being alone. I'm not going to force something that isn't there.
So, my advice is to practice holding yourself back while in the early stages of dating. Dating these days is very different, and, to me, OLD has created a false sense of people. We unintentionally fill in the "missing holes".
If he is going to walk out of your life...let him.
((((GM)))))