Are you sure you are set for trial? Your attorney should have already talked to you about your options because now that your case is on the trial docket and soon to be tried, your options are limited. (In Harris County, as with other counties, many times the State will withdraw their pre-trial offers if the case is set for trial, or raise the offer.)
If the case is reset, it will have to be with the permission of the trial court.
Talk with your lawyer about your feelings about the case and learn if the case is actually set for trial. Discuss your options at this point, and whether there have been offers made to you in the past which the lawyer did not convey to you (which ethically s/he must have conveyed.)
That is unfortunate but it really is up to the judge and your attorney will need to provide a sufficient cause and show it's not to delay justice. You really need to speak with your attorney and make sure your case is a priority to him.