My thought is, that this doesn't sound much like a separation just now. I would sever communication, unless absolutely necessary, and unless he comes to you to talk. I don't mean give him the cold shoulder. I do mean, that it's time to look at what may be a crutch for you or him to hang on. When we first split, my ex and I texted and IMed constantly. It was because it maintained some familiarity for me, and gave her a way to get my help when she wanted it.
He wants to be separate. You need to define for yourself, in unquestionable terms, what that word means. Then you need to stick by that definition. Ween yourself from the marriage tit as it were. I'm betting you're already thinking of how you can handle a lot of the things you text about all by yourself. So, do it. This is the hard part starting in. The actually looking at yourself and changing some major things part.
