Sodie, I'm so sorry you're in this possition, a possition that many women have found themselves to be in, you are not alone with these feelings, but that doesn't help when you are in the midst of it, it is heartbreaking and feels unsolvable, but hang in there, please because you sound awesome.
You will realise as you age that what you felt was important and real in life, as opposed to what he felt was important and what he prioritised was shallow and pathetic, this will take many years to feel vindicated from.
For the meantime, please look after yourself, you will get through this, time will ease your pain and decisions maybe easier to look at in the future, take your time to grow stronger, which you will.
Trauma is just that, an episode of pure hell, with the thoughts and pain ruminating arround your brain like cyclone, try any means possible to divert that pain, imagine he doesn't exist, he was never born, you never met him, or he's dead, it sounds extreme but it could help. Train your brain to cope with the immediate turmoil.
Please take care and remember you are a wonderful woman and we know how you feel, no man is worth this.