Don't take extra science courses to boost your GPA unless you would be interested in taking those courses with an excellent GPA already. That's a bad idea, and you would hate it. Your GPA works for DO programs and should be fine for some MD, including your in-state and some low-mid tier MD.
Have you considered becoming an EMT-B? It's a quick program (4-5 months) and you have some free time (realistically you can't just study MCAT 24/7 for 5 months). It would also give you a lot to talk about during interviews!