I can see where you are coming from with I feel I owe it to him to have a period of time for the relationship to 'disintegrate' in his eyes
What if you looked at it differently? How about you have a period of time for his control to 'disintegrate' in his eyes?
Get your hair cut and coloured. Get a tattoo. Refuse all sex, preferably using his words right back at him "I'm not up for it now and won't be later. Go ahead and have a wank if you want." Argue differently.
Your descriptions of your "discussions" or arguments sounded like brow beatings that continue until you are beaten into submission.
It is completely OK to say your piece then refuse to discuss any further. "I've told you how I feel. I understand your point of view but it doesn't change my opinion. I am not going to engage in any more discussion about this now." Then walk away. This is a very normal way to handle a difference of opinion.
Over many years, I've come to believe that repeated long heavy conversations are a sign of emotional abuse. Normal behaviour is relatively short conversations then you each think about things separately then have another chat after reflection on each other's view point, often at least a day later, perhaps repeating the process of brief exchange then reflect many times.
If I were you I would have all my plans to leave quickly ready before showing him that his control is gone.
Btw, the way he got you to drop your friends to spend more time with him is exactly how abusive men do it. Text book.