What is it about Castles in the Sky that was so difficult for you?

I don't want to say too much or I might give something away. Let's just say the hurt part was easy, the comfort part not so much, and psychological whump is a pain.

The other matter with this story is that it was practice for me as I have several original fic in mind that involve psychological trauma, which I've never really delved into before (at least not this deeply). So this story is a big deal for me in more ways than one. I want to know what people think of it, if what I did worked, if it didn't. Not so much nit-pick it, just let me know if I pulled off what I set out to accomplish - mentally whump then heal Shep.

So of all my fics, if a reader could only pick one to read, I would want them to pick this one.