A: During the course of the tria there will be witnesses you believe are good for your side, and witnesses that the other side brings in that you feel hurt your case. In addition, when your attorney questions your own witnesses you feel good because they are providing testimony that supports your claim. When the defense lawyer gets up to question your witnesses, there may be points during that testimony that appears to be going against you and you will feel bad when that happens.
This is entirely normal and happens in every single trial. I often tell my clients not to pay great attention to the emotional highs and the emotional lows during the course of the trial. Those work themselves out by the end of the case. Also, the judge constantly reminds the jury not to make up their mind during any particular testimony or at the end of each day. Instead, the judge advises the jury to wait until they've heard all the testimony, heard the law as it applies in that particular case and only when they are deliberating, to make up their mind about the case.