Excited to be designing puzzles? It's traumatic (9)
I believe the answer is:
upsetting
'traumatic' is the definition.
'excited to be designing puzzles?' is the wordplay.
'excited' becomes 'up'.
'to be designing puzzles?' becomes 'setting' (as in setting crosswords).
'up'+'setting'='UPSETTING'
'it's' is the link.
(Other definitions for upsetting that I've seen before include "Tipping" , "sad?" , "Likely to put out" , "worrying" , "Distressing" .)