As I see it, being that you failed the class, you probably know where you weren't all that strong in the course. Also, you probably have the course syllabus and schedule for what you were supposed to go over (assignments). I would suggest reviewing the material you weren't so strong with and if you're not so strong with calculations, go over those until you're able to get them done right, every time. Remember, med math isn't that hard, but you have to be accurate!
That's on top of your plan to go do lab work every week. The most important part is that you actually do the work. We all have problems along the way. I was rolled back 2 semesters because I failed 3rd semester and they changed course content on us. I had to follow the content! What happened? Well, I did quite well and had a great time learning things I hadn't gotten the first time through the content and also a great time helping teach my classmates because I already knew that stuff. Remember, when you're able to teach the material, you're at a point where you understand the material pretty well. So, don't despair. That'll suck you right into a massive funk faster than anything. It's an opportunity. Seize it.