I assume from everything you say that this is a Bucks Appeal? I was in your situation on almost exactly the same day 2 years ago, so I really understand how you feel this evening.
A couple of last minute tips. Firstly, although as Guest55 says, the LEA rep says very little, the "statement" lasts longer than you expect. Please remember that it is a completely standard statement, just with your child's scores inserted in the appropriate gaps. There are also a couple of standard questions in the statement about familiarisation papers and special needs. Just answer them at face value and don't start to argue your case at that point - that comes later.
Secondly, take your time when answering the panel's questions. If you are able to, try to work out why
they are asking that particular question? Questions, other than filler questions, are designed to winkle out the important details of your case and I sensed that the panel were really trying to help me put the best of my case forward with their questions.
Very good luck indeed. Please do tell us how you got on.