Since it was a long distance relationship, anything on the computer--chat, skype, etc.--should be permanently removed as they will be a trigger for your and your husband.
Get into Plan A and give it your best efforts. Here you go:
http://www.marriagebuilders.com/graphic/mbi8113_ab.htmland from Pepperband:
The Carrot and the Stick of Plan AThe carrot of Plan A
Meeting your wandering spouse's emotional needs.
Making "home" a warm and inviting place to be.
Placing emphasis on what has worked in the marriage.
Showing consistent self improvement in areas where previously lacking.
Stop lovebusting behaviors.
Communicating with a calm reassuring voice and relaxed body language, even in the center of a verbal storm created by the infidel.
Becoming the person any reasonable spouse would want to come home to.
Remaining open to the possibility of recovery.
Offering forgiveness and understanding.
The stick of Plan AExposing adultery where it matters most. Exposure that takes the form of a swift and sudden unexpected tsunami of truth.
Not apologizing for exposure or speaking the truth in a kind yet direct way.
Directly communicating the hurt and devastation that the affair has caused.
Not accepting blame for the infidel's choice to become adulterous.
Let the consequences of adultery and infidelity fall freely upon the heads of the adulterous.
Establishing boundaries that disallow the affair to effect children of the marriage, financal security of the marriage, and otherwise ruin innocent bystanders.
Standing up to infidelity as a beast that must be slayed for the good of the family.