Hello Markov,
We cannot tell you how to behave at your assessment, other than you need to be honest about the problems you have. If you are worried that you may not remember aspects that you want to get across perhaps a family member or friend could accompany you to support you. They wont be able to answer on your behalf but they could remind you of anything you might forget.
Nothing on this board constitutes legal advice - always consult a professional about specific problems