Welcome to trying to garden in Georgia clay.

I am tilling up my yard for the 3rd time in 3 years, due to the grass keeps dying. I sent a sample to the extension office here in Walton County and found I have absolutly no nitrogen in the soil.
My solution rather than bring in topsoil is this: I am tilling in mulch and creating my own. Most
tree trimming companies around here offer free wood chips/mulch if you haul it. It may take a little longer but much cheaper than truck loads of topsoil($120).
Good luck