Please note that I am not licensed to practice law in the state of Illinois. It depends. If a victim fails to appear in Court, the State's Attorney could request a continuance in order to interview the victim to determine if there has been any intimidation or coercion by the abuser(s).
I have attached a link to the Illinois Coalition Against Domestic Violence for further information. I strongly recommend that you contact an attorney in your local area.
As a victim in a domestic abuse case, you should contact the local District Attorney's Office and speak with the assigned victim advocate. You should explain to them why you no longer want to pursue the charges. If you are subpoenaed to Court, you will have to show up or you may later be arrested. If the State does not drop the charges, then you should consult with a local attorney to discuss your rights.