I have witnessed online relationships slide very quickly from 'friendly correspondence' to 'extreme closeness' to 'explicit closeness' in a matter of weeks. You are lucky that you didn't reach this point, but think of it in 'not online' terms. Six WEEKS is not even a whole season. If you were dating a man in real time, would six weeks have seen you deeply involved yet? Perhaps, perhaps not--I don't know what time frame works for you
I know that for me, six weeks would have me still in the trial phase--how is this working out? Who is this person? We would have had a few dinners out, quite a few quick snacks, probably a number of phone calls, some texts, and met for activities like walks on the beach, all with a lot of face-to-face talking allowing me (and him) time to make a lot of observations.
Is he courteous to strangers? Patient with wait staff? What is his tone of voice like when he speaks of people in his life? If he's divorced, how does he explain the end of that relationship? In short, how does he approach life and is that similar to the way I do?
On the phone, you miss a lot of this; in email you miss almost everything, unless the person chooses to reveal it. The other danger with email is that I may say "black is black" and you read "black can be grey sometimes"--we *interpret* email. No amount of emoticons can fully deal with this. That's what tone of voice, gesture, and expression tell us face to face.
For this reason, I think a person should move even more slowly when developing online relationships than they would in real time. You're working with only partial data, and the tendency is to 'fill it in' from your own side--add what is missing--and you may not even be aware how much of that is going on.
The problem is that the immediacy of the online environment makes people move faster--they send 20 emails in a day and that *seems* like intense, deep, meaningful communication, and it may be--but it may not. There may be huge pieces left out.
For example, not long ago a friend got involved with a woman who "forgot" to mention that she was still married because she "felt divorced". For my friend, a practicing and committed Christian, this was a deal breaker and a very painful episode ensued. How did this very important fact not come up? It actually had--but when he asked the question, she didn't answer it, and there were 10 other questions in that email which she did answer, and that 'detail' slipped aside.