Breakup: How Do I Finally Let Him Go

I have messaged on here before about my ex and appreciate your comments and views on my situation. My ex is part of a social group that we both belong to so it has been really hard for me to move on and heal as i have to see him. I am an organizer in this group and i arrange social events to which he the books onto, which as part of the group he is allowed to do. I have been trying very hard to accommodate this and be civil but he has been begging me for forgiveness and saying that he is sorry and can we try again. I have thought hard about this but every time i trust him a little something will change and he reverts to type. The last time he said he didn't like me stroking a dog. He is now saying that i act differently around certain people and that they "own me". i am not even sure of what this even means. he says it is what he observes as i am different towards him when they are around. I have explained that i feel awkward when i see him as i still feel a lot of hurt as to what he has done but i am also trying to be civil for the sake of our mutual friends and the social group. He said that i am manipulating people against him and one of these friends of mine is my secondary owner (whatever that means). Every time we talk i end up crying and he sits there and says he has done nothing wrong. When we are out he will make comments that only I know what they mean and i therefore stupidly react by making a comment or pulling a face, to which he is now saying i am causing an atmosphere and i have to stop this. But i say no he is doing that on purpose to make me behave in such a way to then make me look the bad one and make him look like the innocent nice guy. The problem i have is i think i know what he is doing but i keep still falling for it when he says he is sorry and regrets what he has done and he loves me. I have told him i do not trust him and it would never work but did want to try and be civil and we get so far and then bam another episode will arise where we end up arguing. He also keeps accusing me of telling too many people what he has done to try and destroy him but i didn't i only told our friends the truth of what he did when they asked what had happened not thinking anything more of it. In hindsight i probably shouldn't have told people too much but i was hurting. I have now blocked him and told him that we are no longer going to be able to talk as he keeps hurting me and i know he is starting to make me look like i am the one causing trouble in our social group and i am starting very much to wonder if he is narcissistic. People have told me that his behavior is very much narcissistic and controlling but i keep thinking no he cant be. What i need help with is now i have blocked him and told him that we can no longer have any chats how do i make sure he doesn't worm his way back into my head when he starts turning up again at my social events. I need to stay strong as i am almost certain what he is doing to me but he keeps trying to make me think he doesn't mean it and he loves me. Does what he has done and said give me any reason to think he is a narc or at least controlling? He dumped me by text after 4 years, said i smell as i only showered once not twice a day and not for more than 15 mins each time, now he says he loves me and he has made a mistake. He also cheated at the beginning of our relationship with 2 people but lied about it and never told me that he did that until after we broke up when i found out from someone else and now he says he is a changed man and he has sorted himself out but then he says things like i am owned by my new friends and that they are filling my head with stuff about him and that i am manipulating people against him......but he loves me???? What is this guy trying to do to me? #breakup #healing