I feel like there have been so many choices I've made that were felt in my body before they became crystallised in my mind.
With regards to the decision of leaving, it began in my body with my libido completely dying due to being overwhelmed by his porn-fuelled fantasies and totally unreasonable expectations as well as feeling oppressed by pressure and coercion. Sex was painful, and then he wanted to make it gross too. I just noped out. Then he continued to binge the same porn behind my back, which made me feel super cucked, and then I wanted to have sex with him even less as a result.
I realised I couldn't trust him in the long term when he told me that certain things that I no longer wanted to do were too important to him in the bedroom and that he couldn't stay in a relationship without them.. the fact that he prioritised his own sexual gratification above me as a partner. That was the moment that the trust died for me.
I remember the moment that things actually began to end for me though.
He was in bed because he had a night shift, and I was about to go and see one of my best friends. I kissed him goodbye and told him I loved him, and as I was getting ready to leave, I just didn't want to leave. I knew full well what he was going to do when I left. I also felt that he was anticipating his next porn binge and had been just waiting for me to leave, and I dunno... something really did just die in me the moment I was walking up the road away from his house just extremely aware of the entire thing. I felt honestly devastated, but I felt like if I carried on allowing myself to be intimately attached to this person, I would just turn into a complete shell of myself, so I just naturally in that moment emotionally detached there and then. I just went from feeling utter shit to totally not even thinking about him again for the entire day. I guess I just severed that bond in my heart as a kinda self-preservating response.

I didn't leave until weeks later, because I wanted to believe it could work out between us.

The moment I actually left was following a health scare that made me re-evaluate my choice of partner in a really intensive way. He would protest this claim, but I felt like it was impossible to please him and I'd only wreck my mind, body and spirit even trying, and that was the ultimate realisation that lead me to end the commitment I'd made to him.
I didn't move on, and I tried to lean in again, and after an extremely intimate night together that felt like the first of something really important, he relapsed a few days later and instead of disclosing voluntarily, he left it for hours. I was feeling depressed all day because my gut told me something was really wrong, and when I tried to ask, he immediately went into gaslighting/defensive mode. That's the moment I was DONE done.
As much as I wanted to work things out, I ultimately realised it would require so much surveillance that it just seemed completely ridiculous to me.
So I left. And that's that really.

Leaving is really a process - I feel like it comes from a breakdown of hope over time.

For me, that moment when I kissed my boyfriend goodbye, that really was a pivotal moment for me. I felt extremely taken for granted, disrespected and honestly, just completely unimportant. It was the moment I realised I didn't want to be with him anymore.