Some marriages work well as room mates after so many years...that bit is not unusual.
What is unusual is his 'can't be bothered' attitude towards you.
If you can't organise date nights or look forward to something together then really he is doing what is practical: having a social life around you not with you. It makes sense. If you aren't fun to be with but moan about him all the time then yes, he is better off spending time with his friends.
Neither of you are willing to compromise by the sound of it. You love your work and as you say, that is part of your identity.
Rather than moan and look at him to 'fix' the situation you would be better off finding your own interests, hobbies, organising fun trips etc whenever you can and go with your son or on your own or a girlfriend.
As may be you are a bit jealous of his social life?
What would he say if you joined him in his activities?
If you want to stay together then I would stop trying to 'fix' him but rather look at yourself and what YOU want to do to change things for the better.
It's easier to blame but in all honesty, unless you want to separate and get your own place given your lifestyle and working hours you would quickly become much more isolated and lonely than you are now!!