Your GPA is your fate, and you're in good shape in that regard. The most important thing is to keep your cumulative undergrad numbers up over 3.7.
The mistakes I most often see at this point in a "career change":
1. Not looking ahead at the schedule. You need to be completely done with your app in June (any June you like). That means your MCAT score is in hand in June, and it's the best score you can possibly get. That means you did your MCAT prep with rigor all spring long as your highest priority, and it means you got the prereqs done in time to do effective MCAT prep. Also it means that you started working on letters of recommendation around Xmas so that they're in hand in June, and you have all your ECs in an impressive state by June. (And then you keep doing ECs during your app year so you have things to talk about at interviews.)
2. Mistake #2 is thinking you're any different from the 21 year olds. By the time your maturity and life experience is relevant, you'll be WAY down a path you can only get on by competing directly with 21 year olds by the standard applied to 21 year olds.
In my strong opinion, you should now be reading health news coverage EVERY DAY and working to build a nuanced and apolitical understanding of the challenges in the US health non-system. (One or two years of this daily practice is a good basic intro to issues that the majority of physicians complain about but don't spend time learning about.) In my strong opinion this is where you can actually demonstrate maturity, in respect for complexity and in humility in the face of overwhelming obstacles. (If you've taken real analysis or game theory, you're well prepared for this challenge.)
Best of luck to you.
