A couple things:
1. You may want to change your profile pic to protect your anonymity on this internet board
2. Retaking courses won't kill you - For MD applications, your grades will just be averaged. For DO, your grade will be replaced
3. It may do you some good to look over biochem over the summer. And review some of the basic rxn concepts from ochem since they will be built on (and gen chem for that matter). There's no need to go crazy pre-prepping, but reading a bit to keep the brain muscles from atrophying may be useful in your case. Also you may want to aggressively update your study methods (practice problems, office hrs, tutor center) to ensure you come out with a strong grade and understanding when you're done.