I'm sorry to hear that you had some struggles during your freshman year. Is it possible to have any of your previous grades officially withdrawn? If you go to the academic advising center on your campus, you might be able to speak with an academic adviser about whether or not you might qualify for a grade forgiveness/course repeat. That is, say you took a chemistry class and failed it. Then you took the same class again the next semester and earned a "C". You might be able to have the first "F" removed from the record on account of having the second grade be passing. Or, if you had a legitimate health crisis, and have documentation to back it up, you might be able to appeal to have some grades or a whole semester removed/withdrawn. This would improve your GPA significantly.
Even if your campus even offers these types of remedies, they wouldn't be done in time for you to improve your GPA for rush going on right now. BUT, it's still a good idea to check on this nonetheless.
Note: I was an Academic Adviser for a major state university for 8 years. I have counseled thousands of students.