CSL, very sorry you are feeling bad, hope you are better soon!
Sometimes you have to vent on your spouse just to get things off your chest, it doesn't really help the sitch (or hurt it) but if you have to for you then you have to.
Sounds like you are taking the right approach and mindset about having no expectations. Like you say he's probably going to flip-flop for quite a while. And you are probably right that separation, as difficult as it is at first, may be best for both of you.