You will never know unless you try formal recruitment this fall. And I think the advice given here is very good...your college GPA at Ole Miss will count more than your high school grades.
My main concern is that you don't know very many sorority women. Are there women on your dorm floor that are new members? If so, you need to introduce yourself to them and express your interest in rushing next fall.
Most importantly, you need to keep your reputation clean the rest of this year and next fall before recruitment. No getting wasted in bars or at frat houses.
I would also recommend going to fraternity and sorority philanthropy events that are open to everyone this spring. Or participating in campus-wide service projects, because I bet there are lots of sorority women participating in them as well.
Good luck and keep us posted!

Heed the above, and let me add 2 more cents. You do NOT need to vomit out your life history when meeting sorority women, whether in real life or during rush. Don't ever lie, but you don't need to volunteer negative information.

Go through rush, and be open to every chapter. I don't think Ole Miss has a THAT chapter, but I'm sure there are chapters that some girls would prefer to not pledge, even over not being Greek at all. Don't be that girl. Any opportunity is a gift.

You may also want to alter some of your info in previous post. You have given too much personal information and most of the chapters will know who you are. Also, private message the poster who quoted your entire thread and ask her to alter it as well.

Good luck in recruitment!