Everyone else has already said it but I'll say it again. . .you are reading too much into this email. It's just an email. Calm down. He is not saying it is over, if it was over he wouldn't even be taking the time to write you an email. What it means is that you are not "there" yet but you already knew that so don't panic.
It's going to be ok. Give him some time and space. I agree with JCJ that maybe turning off the comp would be best for the night. No more IMing because it seems to just stress you out and you don't want to say something you might regret later.
Sleep on it. . .it will look and feel better in the morning.
Although now that I think about it. . .it might already be morning there.
