There is nothing wrong with being emotional, with experiencing the emotions and expressing them - just look at what he has put you through. Stoicism is not your goal here, and there is nothing to be gained from the stiff upper lip.
Detachment should be your goal and it can be attained step by step even while seemingly at the mercy of the fierce emotions you are feeling and will feel. Detachment is letting your anger put a healthy barrier between you and him, his words, his personality, and his behaviour. It's disengaging from him emotionally and psychologically, edging him and his unreason and irrationality from the space it is occupying in your head and making room only for you, for decency, and for order there. It's escaping from the morass he wants to drag you into.
You need to do it because engagement with him is engagement with the toxic. It is hard to do when everything in you wants him to give you an acknowledgement that what he did was utterly wrong, that he defamed you, disrespected you, and treated you terribly but he will not do that. Detachment is the ability to draw a line under what he did and move on without that apology, that closure. It's the process of letting your wound heal itself.
Detachment is how you will put him and what he has done into a box, a 'left luggage office' of sorts, and regain your own identity, reclaim your own individual sense of purpose, reinhabit your own life, on your own.