You should really never be backdashing when you are in the corner. You will be getting hit by fat combos once they see you do this even once. Its just common sense guys. Block his J.c, bait the DP, punish any mistakes, IB blockstrings>360A,B,or 720.
2C does work wonders sometimes in this matchup. If they are going to the air a lot AA 2A will also work.