Hello Sam,
It should not go against you, although I have seen a few assessors claiming that if you can cope with an assessment without difficulties then there is nothing wrong with you!
What I would suggest is that you make any difficulties you are having clear to the assessor during the assessment. So tell him/her if you struggling. Tell them how you are feeling, and if you need to take a break then tell them so.
I hope you have seen our advice to record your assessment.
Catherine
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
