You definitely need an experienced criminal defense attorney, not family law, etc. Contact an attorney in your area ASAP. If you are on Avvo you will be able to find a good lawyer in your area. Good luck!
The public defender's office cannot represent co-defendants in a criminal case. More than likely, one was assigned to the public defender's office and the other was assigned to the alternate counsel or conflict counsel's office or assigned a private/conflict defender.
You should request an administrative hearing within 10 days of your arrest and ask the DMV to provide you with the discovery, which will include the arrest report. If they have received the reports you should receive them within a week or so depending on which driver safety office is involved in your case. Otherwise you will not receive the reports from the court until your arraignment.
You need to get an attorney in your area.