OK, so you're anticipating being a reapplicant, and your GPA isn't that bad, and your MCAT is good.
Generally for a reapp, I advise the following:
1. Get one major new asset, such as doing an SMP (which is what I think you mean by "postbac") or doing a Peace Corps gig, or publishing something. Note that having an asset in progress when you apply, vs. having a completed asset, is a substantial difference, and for this reason you may wish to delay reapplying until you have completed the new asset.
2. Get at least one new letter
3. Update everything - every essay, every 2ry prompt, every activity description. Picture your reviewer pulling up your previous app and comparing it side by side. If you reuse stuff, it looks lazy, and it looks like you're not taking the process seriously. "We rejected you for this app last time, why are you thinking we'd do something different with the same app, resubmitted?"
Since your stats aren't that bad, I think you can be a little bit creative in doing more coursework. You can always find a program. In the "GPA enhancement" sticky at the top of the postbac forum (which is a pretty old list, but a good place to start), there are a bunch of programs in "category 2" that would be appropriate. Programs in "category 1" (SMPs) would also be reasonable, maybe. Nobody here is going to have a definitive answer to "what programs are still open?" so your best bet is going to be to make a list, visit websites, see what's still open, research open programs (reviews in this forum), and get apps out as fast as you can. Note that doing a traditional masters, or an MPH, and/or doing a 2 year program, if there's a subject that interests you, is a completely reasonable thing to do with a decent GPA and good MCAT.
What's going to be difficult is managing your reapp. It's just about mid-June, and you haven't done anything to change your app yet, correct? If you don't want to slow down and wait to reapply, then you need to get your AMCAS reapp submitted this month, hitting the 3 points I mentioned above. Applying early means June - don't screw around with "beating the deadline," that's just wasting money. So you have a very busy week or so ahead of you, and you have to really commit and do a good job putting your apps together knowing that you still might get an acceptance. Just don't even think about whether you're wasting time or app fees. Doing a bunch of work on your contingency plan and "losing" that time & money because you get into med school would be one freaking awesome problem to have.
Best of luck to you.