Well done, OP.
I highly recommend that you try as much as you can not to muse on what he's thinking or what his motivations are. It's totally irrelevant now. When it mattered, he treated you like shit. That's done and it can't be undone.
It still matters now and what is he doing? Manipulation, drama, raising the stakes, high emotion, blackmail, pity parties etc. If he cared about your opinion, he wouldn't be trying everything he can to railroad over it in order to get his own way.
I promise you that you will feel a million times better and clear headed when you get out of this situation. You're taking back control, which means taking back your power, your autonomy, your ability to be confident in your decisions, your self esteem - you're getting YOU back.
Think about what you want, where you want to be in five years. What are your dreams?
I binned a guy off like this. I decided it was the last time I was ever going to be sitting in the bathroom with the door locked sobbing and listening to him charging around yelling about what an ungrateful crazy piece of shit I was.
My favourite thing was doing a Kevin from Home Alone. The bit when he eats all the ice cream and shouts you better come out and stop me. I'd do something I was never allowed to do and I'd call into the empty house hey I'm doing this has anyone got a problem with it?
That silence was genuine bliss.