Aww smiley, I'm so sorry.
I also thought people checked grades before you went through rush, but I guess it's just different at your school.
As to whether you should go through it again, only you can answer that. If you truly feel a connection with Delta Gamma, I'd say go for it. However, if you think the process is just too emotionally difficult, then maybe not. Does DG at your school do COB (continuous open bidding)? Maybe you can try to join that way rather than through formal rush.
I hope you find a home in a sorority somewhere. Best of luck to you, and please keep us posted on what you decide. *hugs*