trying to hit the right emotional key for a scene

Yes, that can be difficult. I find it especially hard in angsty scenes in which more than one character is involved. I can write House sitting on his couch and bathing in angst, and I can write Wilson sitting in his office and having an angst-fest, but give me a scene with two people angsting together, possibly even about issues that hang between them, brrr. That's what I find incredibly hard to write.