When a Jerkface has lost control of you (e.g., when you leave), s/he is all about getting that control back. That means Jerkfaces will say or do pretty much anything to get you back in their clutches - including pretending to understand your pain, promising never to hurt you again, even volunteering to go to therapy.
When you're being treated badly, you get to do what you want, the way you want it, in order to get your life back. No one needs to like or understand anything you do.
It's not the 50s. There are options now. You can choose to be with someone who makes your life easier, not harder.
Jerkfaces aren’t logical. You can’t reason with them, because they aren’t reasonable. They see the world differently than we do. In their world, there are only winners and losers. And if they aren’t “winning,” as in one-upping you and making you cry, then guess what? They’re “losing.”