Nervous and easily upset (6,6)
I believe the answer is:
highly strung
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">nervous and easily upset</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for highly strung that I've seen before include "like the violino piccolo" , "Nervous, easily upset" , "Tense and easily upset" , "Excitable - easily upset" , "Very nervous or volatile" .)