Like chirurgeon, I too suffered greatly during my pre-clinical years - had to repeat a course my first year. I actually took a semester off to do research, then repeated that course. Although it was tough psychologically to do so, I think in hindsight, it was the right thing to do. Part of my problem was that I was too social and was way too involved in activities/gossip/etc. in my original class. By getting a fresh start, I could pick and choose my study partners, and stick with my real friends. I passed second year about the middle of the class, did OK on Step 1 (nothing spectacular - 198) aced 3rd yr (mostly high pass and honors), passed step 2 (202), and matched at the #1 ranked (US News and World Reports - take it with a grain of salt) program in my field. I'm now practicing and no one has ever asked me about my performance during medical school.
Granted, if you are thinking Derm, Opthal, Ortho, Plastics, or some other really competitive field, your first year grades will count. BUT - you still have your boards, LORs, research, personal statement, and networking skills to strengthen your application. I for one worked harder because of my first year. AND no one would have guessed during my 3rd year that I had any difficulty at all. SO - don't obsess. The worst thing to do is to get caught up in your pride and care too much about what other people think or do.
Really, just improve the things you can improve. It'll make you a better physician and a person.
let me get off my soap box now...