Damn, sorry to hear it man.
For whatever this is worth, most of my major purchases are still from local stores vs. GC. I know you're leaning away from retail, but even if you decide to keep that end of it, a LOT of people will go to GC to look, but not buy. The guitars arent well taken care of, the environment kinda sucks, and the prices are actually HIGH compared to either of my large local shops.
That says nothing about instruction, I really cant see GC competing with you in that area so long as people know you're an option, you'll be the first choice 90% of the time. I could be wrong, of course, but I do think that so long as you do what you can to keep your name out there, you'll see minimal impact from the big bad GC.