Closure conversation with ex after 1 year and a half

me and my ex have been broken up for 19 months now, he has another girlfriend (for almost 1 year and a half as well) and everything and yet i’m still here heartbroken as ***.

the thing is, we had a bit of a weird breakup. from him stalking my socials every week up until june, to him reaching out every 2 months, to him coming to my events, to us making out and more while he has a girlfriend (he claims he’s in an open relationship but i have my doubts), it was never the way it was supposed to go. and it wasn’t even the first time we broke up, in fact it was the third.

for 4 years and a half now, we have been going through this hot and cold stuff and now being broken up for 1 year and a half (the longest ever), it still remains hard for me to believe that he’s not coming back, because that’s my brain is trained to believe.

now, a few days ago, i once again woke up in his bed after night out and we once again did some stuff that his girlfriend wouldn’t like (i think?). so we said that we have to talk. next week we’re going to have a “closure” conversation and i just can’t help but be scared.

i don’t want to have it, ‘cause i know that whatever he’s going to say, i’m not going to want to hear it. which is maybe exactly why we should have it. because i need to literally be waken up from my thoughts and i need everything to end in order to be able to heal and move on in peace without constantly waiting for him to text me or reach out or more.

does anyone have tips to deal with this stress and unhealthy healing?