I think by and large, more men than women rush into a new "relationship". It is more aptly called "complication", which they swear blind is "work stress" (mind you, I suppose it is if they're working, fucking, lying and cheating) before, or some might cynically say, "after" a marriage ends.
Oftentimes the marriage is over but, because they are inundated with "work stress", it somehow slipped their mind to mention it. And then the lying has gone on so long they've long since forgotten how to tell the truth. Apparently this spares our feelings.
In actualment, it just exascebates those feelings of going mad, drills into our anxiety for them and perpetuates our belief that they are decent people.
I also know that when your husband fucks off out of the blue, it is just the first day in a long line of horrific ones coming up. Learning of a "complication", learning they quickly get nasty (and miserly) and hanging around waiting for some semblence of truth to emerge is a dreadful experience.
But because so many if us have survived this experience, we can only recommend ways to survive it. I hated the whole experience but I'm mighty glad he left now.
knowing that it WILL get easier is only because women here kept coming back and saying so.
In the interim, don't believe a word he says, trust your instincts, and protect yourself at every step. They get nasty quickly.