I dont think you really can. I think theres a self protective part deep in you that knows your ex is being ridiculous and unfair. And thats why its impossible to follow stepford wifey techniques perfectly to win back a pos that is vilifying and gaslighting you and victimizing himself so that he can end a marriage without guilt.
I read posters like you and kitcat, and i cant believe that i once thought similarly to you regarding dealing with my ex's sh!tty and disrespectful treatmemt of me. I remember telling the family members that loved and cared about me the same arguments that you guys are telling me here to justify your spouses behavior.
(I later found out the truth about the double life he had been leading for years)
If i could go back i would have accepted what he said and realized that there are tons of people out there that will appreciate me despite my flaws because i am a loyal, honest, moral, and committed person. And if they could not then thats their issue. Let them go and search for a unicorn