That's awesome! I worked fast food in my younger days and ended up trying the drive thru a few times after working there for months, and I actually found it wasn't as scary as I thought it would be! I actually ended up working the drive thru a lot for the rest of my time there (sometimes for a whole shift) and really enjoyed it! It's kind of nice because you're not face-to-face with them, so they couldn't see my disfluency when it occurred and I could wait to hit the talk button until I was good to go. In the end I found it even improved my day-to-day fluency. You might be surprised!