(I have not read this whole thread so if this has already been addressed, well, sorry)
Alorna,
If you not having enough sex with your spouse drove him to porn then you owe it to him to stick by him and help him with his addiction. However, if you think there could be abuse or violence toward you and/or your kids, then get the heck out of there. Don't tell him, just go to a shelter and get yourself a VPO (Victims Protective Order).
Just remember the famous words of President Hairdog, "not all men are pigs".....just the ones who aren't getting laid enough! :-)