standing up to my cheating ex (updated)

he cheated on me emotionally from october to february with his ex under the guise of "just friends". i always felt uncomfortable about their "friendship" and voiced concern and asked for him to set clear boundaries with her but those requests were met with anger and defensiveness. he called me controlling and toxic. i later found out they slept together 3+ times in october (he only told me the details of two times but i know he slept with her another time when he visited her behind my back for a few days in september). i found out about everything by accident in may and ended things but he kept convincing me to stay, saying he'll fix it all. stupidly i did, but i kept finding more things out the hard way and still felt very much in the dark about things. he started therapy for his dishonesty but i still felt like he was hiding things from me. finally, i'm standing up for myself and calling him out on his bullshit. sorry if it doesn't really make sense i'm feeling so much i'm shaking and can't really think clearly because of the adrenaline of confronting him about his emotional abuse towards me.

update: after a whole evening and day of him calling every hour, he messaged me this on instagram. seems like i finally got through to him. i'm pretty sad about all this, he really felt like somebody i saw myself marrying and we went through so much together. i love his family, they were like my own... but i know things needed to end for sure.