Could it be that someone points the finger, lashes out at you and really unleashes thunderous cascades of shittiness because of their own self-loathing? Ranting about how awful all these other people in your life have been, and how he is so different, so very different. Not a cheater, not a liar, not someone who would hurt you. No, someone who would never hurt you. Never do anything to cause you a moment of grief. Never stop trying to do everything to make you happy. But he knows he will never make you happy because he knows full well what he is doing to negate that happiness. He reflects on all the things he has done and all the lies he told you – even if he was just trying to stroke his own fragile ego, even if he was just hedging his bets for when he fucked everything up (has to have somewhere to run when that happens), even if he was actually just playing you all along. Somewhere he finds the courage to go on with the charade because, oh, what a material loss to somehow alienate the consolation prize he has so cultivated and played.
You only asked for a time free of lies. After all, as he himself points out repeatedly, there were so many “bad people” who came before him. In most cases, though, at least those monstrosities were honest about and lived fully in the light of their asshole nature. It was visible. At least they did not pretend to be madly in love with you or secretly juggle other people on the side (no, they did that openly). They may have hedged their bets, but they did so openly. They gave you a choice as to whether you wanted to play the game rather than just playing you.
You’re not stupid. You’re just a consolation prize and you’ll do for now. You knew better.