Someone told me that the hardest part of writing was getting the character to step out of the car. The practical stuff. Moving people from one spot to another. I read that Hemingway felt the dragging slowness of writing was the hardest part. And someone else suggested the hardest part was knowing what to leave out. Or starting. Or knowing when to stop.
For me the hardest part of writing a novel is letting the characters fail, letting them fail to communicate, letting them fail to understand, letting them lose for more than a scene. It’s a novel, they work well with an arc. But when my characters hurt, particularly when they hurt because of something they did to themselves, I just want to make them all better. Right now. It turns out that doesn’t work. Not well.