I’m really sorry to hear how you are feeling 
Whilst I’m waiting to hear back from Eric (and I’m not giving up until I’m sure what you are describing is a technically feasible explanation for why you can’t access sync store from DTTG) for future reference please allow me to point you to point you to this thread for ideas for a future backup strategy. If your data is in any way important, you really do need to have backups of it (I’m saying that in the kindest voice I can muster; I understand you are hurting just now).