when filing a complaint for car accident in GA. can you sue the insurance company directly

No.  You must name and sue the tortfeasor in an automobile accident.  Insurance companies must be served and put on notice of the suit though.  The laws surrounding automobile lawsuits and the civil practice act can be very complex.  I would highly recommend you find a good lawyer and see if they are interested in taking your case on.  The added benefit of a lawyer will more than pay for the cost of the lawyer's services.