This most recent DUI will likely count as your second DUI. Depending on the County (and more importantly) the Judge, incarceration is absolutely a possibility.
You have several issues to deal with.
First is your driving privilege. With a .18 BrAC (Breath Alcohol Content), you will be facing at a minimum either a 90 day complete suspension of your license (or privilege to drive) or interlock device (breath test hooked up to your car) for a minimum of one year.
If you are facing DUI charges and want Scott to take a look at your case, complete the DUI Case Evaluation Form and Scott will contact you.