Thanks for the contribution, Cowgirl:
You've already made the greatest stride you could in reaching your goal; you've committed! The biggest obstacle you have is to train prudently, but safely. Enough to get you to the half-marathon Finish Line comfortably (relatively speaking) and uninjured!
You might check www.runbravo.com and adopt one of the training regimens that suits your ability level, time availability, and lifestyle. If it's the HALF MARATHON 3-DAY/week (or 4-Day/week) program, start with number of weeks left 'til the race, and go forward to raceday. I'd suggest if your mileage per week is not as high as 20, go with 4-Day/week plan, as you'll have fewer long efforts, but "steel" yourself to the commitment (mentally and physically) of being out there 3 hours plus with more efforts prior to raceday.
All my best to you, athlete, and thanks for being in touch! Mark