You feel guilty about applying discipline ... he knows this and plays on it .. you feel even worse .. he plays on it even more.....

Its a battle he is winning. Unfortunately the only answer is tough love.
He must learn, the hard way if neccessary, that you are the boss and your word is law. Otherwise things will just get worse.
Believe it or not .. 48 hours of extreme hard work will ensure results . the only thing is .. and this is critical ... both your and your hubby MUST be exactly the same on ALL matters, or he'll play one against the other. and you'll end up fighting each other.
I came home from a detachment many moons ago to exactly this situation ... my wife had allowed things to go soft as the lad seemed to upset at me being away ... clever lad was playing it for all it was worth .. aged 5 !!! None of us enjoyed the following 48 hours, but once he realised he would not get his own way normality returned.
23 years later we still get on and he takes me to the pub to buy me a beer

It might sound daft .. but right now he needs you to be a parent .. not a friend .... too many folks try to be their kids friend .. don't work IMHO ...
