Usage of 'mortally'

I am mortally surprised.

How does this line sound to you? Is it OK to say so? Please help.

Hi Daemon

That sounds awkward to my ear. ‘Mortally’ is used in a few extremely typical collocations, so maybe that’s the only reason that ‘mortally surprised’ sounds odd to me.

These would sound very typical to me:

  • mortally afraid
  • mortally wounded
    .

Hi, Amy

Does it sound “poetic” to you ?
I know that poets resort to weird collocations to make special effects, but at the same time some weird collocations are just plain mistakes by non-native speakers. So which is it?