C.W.
It might be time for a bit a shock treatment for your husband. If you have family or friends close by who wouldnt mind a guest for a little while how about going to stay with someone for a bit. I know sounds bad but it might get your husband to see that you mean it when you say you need his help. This way he gets to see what you do besides just take care of your son. Also he may think that you wont leave because you to have a child. If you do go to someone else's for a bit he will see that you are willing to take extreme measures to get his attention.
Another thing you can do is take your son into the room your dh plays his game and leave him in there with your Dh while you go out or pick up around the house.
Then of course talking and even suggesting marriage counseling might work.