You are to be commended for your efforts in trying to understand and help with the situation you are living in. But, I will say this, you can lead a horse to the water, but you can't make him drink. I am not going to repeat what the other CP'ers have written, but I will tell you he could also be silently grieving for his old self. I can only assume that prior to all of this he was active outgoing person. My physochologist explained to me some the feelings I was experiencing once I got past the denial stage. We grieve because our worlds are turned upside down, we are unable to do so many things that we no longer can, we feel worthless, we go thru the why me stage, we end up with so much anger. Between seeing her and being put on an antidepressant, my life became much better in terms of how I saw things and how I felt about myself.
He is so wrapped up in himself that he cannot see what he is doing to you and the children. Without some type of physchological intervention I don't see your situation improving for you because he is so hell bent for the path he is on. I mean if the 2 of you had a good relationship prior to this, I am not understanding him turning on you. I think this is something being overlooked here on the forum.
Personally, I would have to set him down and tell him exactly how I felt, how its affecting the family, how he has shut everyone out and its the very people that want to him him in any way. I would make it clear that yes he does a problem and everyone is willing to help in some way but he cannot just turn on his family any longer the way he has without repercussions he may not like. Somehow, he needs to be shocked out of where he is now. Three years is a long time to have to sit by and watch what you have. Truthfully, I think the longer he sits and stews in his pot the worse he is going to get without some form of dire intervention. Its all his way and has been far too long.
You are right in how this has not only affected him, but you, your children, its not healthy. Your children are already sick of it and you don't need them acting out because of him, sorry, I am being honest, but he is not the only person involved here. You must think of yourself and your children.
Until this man decides he needs to get help and be a willing participant, I do not see your situation getting better, not after this amt of time. I doubt very seriously he will find his cure on the internet either. How can he sit with a bad back for hours is beyond me. Sitting is one of the worst things we can do because it puts so much pressure on the spine.
Please do come here and let us know how things are. We will be here for you any time....Susie