Do not speak to the police without your own lawyer your hire being present. Instead of contacting the police on your own the better course would be for you to contact a criminal defense attorney right away. Hire him or her. Get a plan in place.
You do not have to speak to police. The police will complete their investigation, and forward reports to the prosecutor, who will determine whether to file a criminal complaint against you. The police may also attempt to obtain an arrest warrant. There are defenses you can assert in your case. It is not as cut and dry as you may think. Please note that if you are arrested, never offer any information to the police. Request to speak with an attorney immediately. You should strongly consider hiring an attorney immediately to evaluate the case and to determine the status of the investigation and the case.