Burned out after a semester? Uh oh. I know for aoa FP you'll be fine, I know people that took extra years for failing, some that failed step 1 or 2 and matched IM and EM. One failed class with a passing remediation won't kill you for FP but you CANT FAIL AGAIN. The reasoning is that you may not be a competent resident because you seemingly can't keep up or you won't pass you're licensing exams. If you just concentrate on learning what you can, study really hard for the boards and do well, then you should be fine if you don't fail anymore. If you do better than average on the DO or MD step 1 and 2 you won't have to worry at all about your preclinical grades. The culmination of m1 and m2 comes down to your boards basically because that's the most objective measure of your preclinical and clinical education. Good luck. Study and find balance in your life.