slit my wrist at work after having a light fitting cover fall on me

on the 17/12/09 i was  asked to change a  light  bulb in the toilets at  work  and agreed to do  so  with one of  my fellow  work mates  we ventured off 2 change some bulbs  upon discovering the bulbs that were  blown  i ask  how the covers are removed and was   told they needed to be turned 2 or 3  turns  to unscreew the larg   glass cover  so upon reaching up  and touching the glass cover it became dislodged at the slightest touch  as it fell it split in half on my head as the broken   picese made their  way  towars the  floor one of the   chunck  caught  my  arm  resulting in an a  trip to casualty   five stitches later  and a  consultation with a  plastic surgeion  over a damaged tendon 
i dont no what  to do next  as  i was  changing a light bulb  i am not a  qualified electrition and i was  working above head hight without  a step ladder  but i was  compleatly un aware  of this  before i said i would   do the  job needed   i  understand it  should of been my  employers not to  have   put me  in sutch  a situation  ....  any  help   is apreciated