Gather all his crap, pile it in the garage and have him take it. I can see him carrying on this little game of "I need my toothpick, I need my screwdriver" crap as long as he can. Right now you need your space and his popping in and out of your life isn't letting get to the emotional state that you want.
As far as the porn, guys are visual, females are emotional... he is bored with his sex life so he goes to porn to find something new and exciting..... 3 or 4 times a week is alot IMHO. When men watch porn they enter a fantasy world, When their actual life doesn't live up to what they see online, they get resentful. Most men need sex.. Not just a woman that will just lay down and spread their legs, they need a woman that is into it.. Someone that will dress up sexy or offer to try something new.... Women need conversation, relaxation.... in order to get into the mood... So what you end up with is one of the main problems between men/women. You give me this and then I'll give you that b.s...
Well I suggest you just work on yourself, figure out what you need to fix. Get some new hobbies, start exercising, take care of your kids (they need a stable parent more than anything right now) and find your happiness. If he comes back, You are in CONTROL of the life you want to have.
