Withdrew from Biochem & getting a W. What now?

I thought I was in my last semester until I just decided to withdraw from my Biochem class. I overestimated the amount of work I needed to devote at took too much work and volunteering on. I was on a upward trend and now will have one additional semester left: retaking Biochem and a Statistics class. This W and a C+ in the semester prior in Ochem 2 does not leave me with an upward trend. What should I do? Should I take more advanced Biology classes (although I would be done with my premed prerequisites) to prove to Med schools that I am a good investment?