I know a lot of girls at IU who rushed as sophomores who had successful recruitments. Some of them were rushing for the first time, but some were re- rushing. Yes its competitive, but you got a bid the first time and now that your grades are better hopefully you will again! I think the most important thing is to just be honest with the houses and tell them what happened. They will be glad that you worked hard to get your grades up!
I wish you the best of luck! And I know everyone here would be interested in your recruitment story when the time comes if you feel like sharing