It's not just that he is controlling he is clearly entrenched in a pattern of blaming the OP/second guessing the OP/ jealousy of the OP's relationship with the children, he jumped on hints that the problem is hers during the one counselling session they have had, and shows determined defensiveness when she tries to talk with him on their own about problems she perceives such as him spending all evening on the computer his response there is to turn that accusation right back on her. And there is the punishing by withdrawal or sulking that seems to accompany all her efforts to open a conversation, to challenge him, to change things including the voicing of her feelings during the one session they have had.
I think this man has clearly decided it will be his way or the highway and that OP will have more of the unpleasantness that has resulted from the initial session if they continue. Joint counselling will be very distressing for Feelok until she goes to individual counselling and learns more about herself and how she functions in this relationship and something of the relationship dynamics and the rules he is playing by. For her part, her perception of her role and her expectations of marriage need to be examined before any joint counselling occurs because I think she is too inclined to think she doesn't have a right to a relationship that makes her happy to the same extent that her H does. If behaviour of the H is making you unhappy, Feelok, then you have the right to ask him to change that behaviour. If he had been like this when you first knew him and you had to fight for his attention against a computer every evening, would you have married him? In other words, are you really changing him, or are you correcting behaviour or habits of his that have developed over time and are now hurting you?
'I know there's a fine line between wanting to change the other person and wanting to improve things. I have a feeling though that h sees nothing wrong with being as solitary and kind of introverted as he is....
...For my part the changes I would want are a. for us to be able to communicate how we feel about things without being defensive and with affection and b. for him to lose his short tempered and critical side and for him never to ostracise me again...
...I think he wants a tidy house and to feel like his opinion is valued more. I find this difficult because it slips over into the autocratic thing. We have issues over money and spending as well and I suppose all that could be talked about and aired, but have a feeling it would be / will be terribly harrowing so don't know if I can go there!'
This is a power imbalance and emotional abuse in a nutshell. It is a serious problem and I think Feelok knows this. The insistence on the tidy house is in deed an autocratic thing. It is a stick to beat her with. The H here is getting what he needs (or what he thinks he needs) out of the status quo and he feels threatened by her attempts to change things, and he conducts himself without regard for what she wants or needs. In a healthy relationship, no matter what the issues, the couple would be able to talk without fear of reprisals, whether those reprisals consisted of physical or emotional or psychological abuse. Withdrawing/ sulking/ giving the silent treatment/ putting down Feelok in front of her child -- all this is emotional and psychological abuse.
I would hazard a guess that the problems he has in his perception of her as a mother are also related to his desire to keep things as he likes them, with Feelok threatening his center-of-the-universe status when she behaves as a mother to the children instead of orbiting around him.
Someone who has got sort of used to this treatment really should have counselling on her own as a kind of consciousness raising exercise before she sits down with a counsellor and her H and tries to put her point across.
Joint counselliong without individual counselling to bounce the counselling experience off someone with perhaps an alternative pov to that of the joint counsellor would help enormously to get a better perspective. Joint counselling with someone who holds the views the counsellor has expressed would be like walking into the lions' den. You would be eaten alive by both your H and the counsellor. You would emerge feeling you had been mugged. I have been there and i have had that feeling and I don't recommend it.
It is really hard to hold your ground against a man who thinks the best way forward is staunch defence and the best defence is attack. If you decide after a few sessions of joint counselling that you are not being heard during the sessions, having your perceptions questioned, having your H look at things in the light of attack-defend instead of moving forward together and climbing down from the mutual blame game, having your temerity in raising issues rewarded by punishment at home, you will be accused of dragging him to counselling and then wanting to squirm out of it when you don't feel it is going your way. Been there, done that, got saddled with blame for refusing to continue with the allegedly great counselling...
Maybe go to several sessions of your own before you agree to go to the joint counselling if you really think you should continue with it.