You definitely need to go to the ER. Your glucose level is getting dangerously high, and you could go into what is termed diabetic ketoacidosis. This is a very serious condition that can cause serious damage to your body and possibly death if not treated immediately. You need to find someone to take you to the ER, or call for an ambulance...DO NOT drive yourself there because you could lapse into a diabetic coma while at the wheel and cause a serious accident.
With a glucose level of 393 I do not believe you can be diagnosed as "pre-diabetic" any longer.
Please seek treatment immediately.