As a witness for the State, you may be questioned by the State's Attorney and then by the Defendant's attorney, who will cross-examine you (ask you additional questions). You may feel, during the questioning, that your testimony is under suspicion, or that your personal motives are doubted, but the process of cross-examination is not meant as a personal attack towards you. It is to ensure that all sides of the case are told, and to establish the truth.
The Judge is there to assist you if you do not understand a question and to see that you are treated respectfully. If you do not understand a question, do not be afraid to say so.