Don't beat yourself up. I don't know the details of your sitch, but judging from your timeline, I would plausibly guess that your husband's request for "space" was the usual script which can be translated:
"I need space in which to conduct my affair, unencumbered."
I'm not saying that any begging/pleading/pursuit was the right thing to do, but had you done the opposite, it likely would have been even worse.
