Guilt is in the eye of the beholder and you sound like you think you are guilty of something. She is soon to by your Ex wife so what are you worried about.
I don't see sexting as fault grounds for divorce. Keep it in your pants and save your money for the divorce. And don't let your wife have access to your phone. If you did not commit adultery then let her investigate all she wants.Under Virginia Code §20-91, a divorce may be granted based on the fault ground of adultery, or sodomy or buggery committed outside the marriage. The crime of adultery is defined in Virginia Code §18.2-365 as a married person voluntarily engaging in sexual intercourse with a person not his or her spouse.
Recrimination is also a defense to adultery. A plea of recrimination may be raised when the other spouse is also guilty of a fault ground for divorce. In effect, the mutual fault bars either party from obtaining a divorce based on fault.

