Sonic
re your comment:-
"I stay because I think of our wedding day and how things used to be, because like today he is doing the washing for once and got my son dressed and to nursery whilst I am writing reports because i was ill in the night. He cooks - albeit what he wants and really late. My ds adores him and he adores my son".
Your wedding day was just that; one day. Such men like yours also do not change; are you waiting for change, for him to somehow morph back into Mr Nice All the Time Person. That was an act he put on for you. He is no decent example of a father figure either to his son, you really want him potentially growing up like his dad?.
Look properly at your marriage now. There is no intimacy or relationship to speak of. Problems also include his previous use of gay porn and his current drinking level. Not to mention his financial and emotional abuse as well. He has also smashed your belongings (I note not his); that is actually classed as domestic violence.
How can he be capable of looking after his son?. He is not above having a shout at you for being late because you walked home with a friend and you forgot to tell him. You do realise that such behaviour from him is rooted in power and control and thus abusive. He seems more like your jailer than your husband. He won't be "happy" until he has completely destroyed your life.
He is now doing the barest of bare minimums (to really keep you in line and unquestioning) and you seem sadly grateful he is even doing that.
He gets what he wants out of this but what is the attraction for you now, what do you get out of this relationship?.
None of what you write including the above are any reason at all for staying within this; you're just going to end up teaching your son really bad life lessons about relationships as well.
Why is your relationship bar so low; staying with this man will lead only to more misery for you and in turn your son. I would also state that your guilt from years ago is completely misplaced (I think that was you actually trying to get out of this bad relationship but you did not make that leap). He should be the one feeling guilty here and he does not.
Please talk to Womens Aid on 0808 2000 247 as they can and will help you.