He doesn’t see it as controlling behaviour
That's your answer.
He has got to own it, want to change and seek out therapy for himself to address it. (Not go to couple's therapy because you have made it a condition of continuing the relationship).
It would take a LOT of work on his part to do this and there will always be trigger points or flash points in the relationship that would cause him to feel the need to control and he would have to employ a lot of mental energy a and emotional strength to do that.
He would only do that if he recognised the behaviour as controlling. Which he doesn’t. And wanted deperately to change it.
I'm going to give you an analogy.
I am an untidy person. I would love to be a naturally tidy and organised person. I recognise my untidiness.
A couple of years ago, I spent a lot of time and effort on becoming orgnaised. I cleared out cupboards, got a skip! Emptied the loft and the garage, bought boxes to keep things in, followed methods to keep on top of things...
Two years on, my house is tidy. My workspace is tidy. But its a constant effort and I still have disorganised cupboards because im not a naturally tidy person. It's a constant effort to keep the house tidy. I have to really psyche myself up to keep on top of things.
I put the effort in because its what I want. Not because someone else has asked ot of me and I can superficially appear to be a tidy person but I'm still not really.
Now apply that to him... the controlling tendancies will always be there. He will just have to keep them suppressed and to recognise they are wrong and want to not be a controlling person.
But, in your own words, He doesn’t see it as controlling behaviour.