| To kind of echo what Lyrical says -- and I hate to say it, because you've said yourself that it's already kind of obvious to you -- get the grades up. :\ Grades matter a great deal to recruiters in most industries, and they certainly matter to MBA and PhD programs. If McCombs thinks you can't handle the curriculum now, they'll never let you into their MBA program. You are probably bright and extremely capable of doing well, but the only metric they have to go by is your grades. If your grades are bad, they won't even stop to consider the rest of your application. They'll move onto the next file in a heartbeat.
If making a concerted effort to bring up your GPA means dropping one or two extracurricular commitments, then so be it. Extracurricular involvement looks fine on an application or to a job recruiter, but grades are far more important. Like, an order of magnitude more important. I'd suggest taking an honest, critical look at your club and activity involvement and seeing what cuts can and should be made. I'd also hold off on starting any new involvements at this point. Your grades should be occupying 100% of your time right now, or close to it. If 90% isn't going to push them up, then you need to allocate more than 90% of your time and resources to the task.
This is especially important if you're applying to an MBA program after your current program. MBA programs like to see students who know how to manage their time effectively. This means not overextending yourself in club involvement at the expense of academic performance. Even if that's not what's going on, they'll look at your GPA and read you that way. | 