From the question, I assume that the mediation did not work out and that you did not end up with a settlement? The mediator and your lawyers will have explained that the mediation process is confidential. This includes any information that you learn during the mediation.
You cannot unlearn what has been learnt, but you cannot make reference to any information from the mediation during your court case. Consult with your lawyers as the Mediation Ordinance does provide for disclosure in certain circumstances.