How long/how often are you seeing him for just now and what is he suggesting you start reducing to? At the moment he says he just wants to discuss it and your reaction (feeling like you're being held down and punched in the head) suggests you don't want to hear/talk about it. So even having the conversation about the ending process is unbearable but it's part of his job to help you leave him so he needs to keep coming back to an ending process.

A year is a long time in some ways but will go quickly too so he is being responsible by keeping bringing things back to ending.