Make a LOT of phone calls Brian but I'm pretty sure that you'll basically have to start over again.
6 months is not a long time trucking in the eyes of trucking companies. I've talked to people who's driven for 10 years stopped for 5 and lots of trucking companies won't touch him without updated CDL school training.
I know Averitt Express has a refresher course. Don't know what the requirements are.
GTCC will be starting a class early next year. But the cut of for enrolling is far advance of start date.