Yes, that does sound like you've been dark for quite a while..... Did your husband date a lot of women before he met you? What do you think first attracted him to you? Do you have any idea of what might be attracting him to OW?
Like you, I've got an extremely overactive imagination (although I'm a Leo). I think in a situation like this it's wise to consider all possiblilities and get used to the idea that those are words you may hear.
There is no arriving, ever. It is all a continual becoming.