Could I really have fallen in love with a lie? Did I get engaged to something that didn't exist? Did I imagine a life with someone that wasn't real?
I just can't take the pai. Anymore.
Yes, the hardest part for me was accepting that I was in an extremely close intimate relationship with someone with a serious mental illness. That was a serious wake-up call, like what the hell? Didn't make it hurt any less knowing that, made it worse initially. But it's true. And you didn't fall in live with a lie, you took one side of a split personality, the one that was mirroring the good in you, and then in turn projected your good onto it, and fell in love with that. Mindfck I realize, but realize that what you actually fell in love with was YOU, as reflected back to you. Take that in.
Learning about the clinical side of the disorder really helped me depersonalize what happened; it could have happened to anyone, or a wet mop for that matter, it's not about us.
So. It's not about you, and if he is with someone else, remind yourself that they are in the idealization stage and you are in the the devaluation stage of the disorder; it's the flow-through system from hell, and there is plenty of pain awaiting the new victim. Work hard and focusing away from him, stay strong, stay here, take care of you.