As a general rule, if a couple are having "groundhog" day conversations where grievances are aired and empty promises to change are made, something pretty drastic needs to happen to "change the script". This could be what your counsellor is getting at - that you have both got yourself locked in a state of permanent "replay". She is helping you to look for what catalyst will change the script.
People also need an incentive to change and normally the biggest incentive for someone who loves their partner is the threat of losing them. Ideally, however, the incentive should be that the behaviour is making you very unhappy. That in itself should be the most powerful incentive to change. If it isn't, it usually means that at heart, the person is selfish and puts his own needs above yours.
I really wouldn't recommend using a withdrawal of sex, because using sex as a bargaining tool/weapon is an awful practice and adds to the downward spiral.
I also don't recommend ultimatums unless you are prepared to follow them through and it doesn't sound as though you are yet in that place.
Perhaps then in therapy you need to tackle what is at the root cause of this behaviour. It sounds like extreme selfishness to me, mixed in with pride. It doesn't sound like he can admit that he is a very poor time manager, or that his stress is self-generated, or even that this might be the wrong career choice for him.
When it gets to the stage where he stands to lose what presumably is his most important relationship, everything should be up for discussion, including his career choices.
I would echo what everyone has said in that bringing children into the mix while this is unresolved will be disastrous. Selfish people generally get worse after having children, not better - and their selfishness actually becomes even more apparent.
So, I would start to look at his selfishness more laterally. I'd bet it manifests itself in all sorts of other ways i.e. not going to places/seeing friends if you want to but he doesn't, not pulling his weight domestically, failing to make effort with relationships in the extended family, believing his career and work are more important than yours. This is, I suspect at the root cause of his ultimately fruitless workaholism.
I would also add another dynamic to the mix. I have noticed throughout life that often people "hide" behind their busy lives, either as a mask for not doing things they'd rather not (but should) or if they are trying to avoid confronting something they cannot handle; an unsatisfying relationship normally. There could be something going on here too.
Having explored selfishness and "hiding", you might conclude what I do - that actually this is very controlling behaviour. He might not see it like this and I suspect you will take some convincing that it is, because it is very subtle. But if someone keeps doing things that make another person unhappy, affecting their choices in life, it is controlling.
See where this takes you with the counsellor and him. And perhaps explore the truth that his incentive to change should be as simple as he is making you unhappy. A good question in this situation is:
Why that hasn't been enough of an incentive in the past?
I suspect if you phrase it this way, it becomes a rhetorical question.
Good luck!