Not sure what to do going forward

I'm currently in my last bachelor's degree semester and have already applied to some ABSNS. I made the decision to go into nursing last semester, making it kinda rushed for me to get in all the prereqs in time before the programs start. One of the prereq's im taking right now is A&P I but it's been a struggle for me to maintain a good grade in this class as I'm trying to balance it with all the other classes I'm taking right now. Seems like I thought I could take all these classes and do fine, but I bit off more than I could chew. At this rate, I'm getting concerned that I might not even pass this A&P I class which has been seen to be notoriously harder at my uni compared to other schools. Right now, I'm considering the worst-case scenario of failing this class, and not sure what my other options will be now. The due date for withdrawal has passed already, but I may try to see if I can get an exception on it (the first time I would withdraw from a class). I'm wondering if it would be OK if I withdraw (or just fail) and tell the admissions office that I would like to swap the prereq with another class that I would take over the Summer which fulfills the same requirement. I'm not sure how badly this negatively affects my admission chance, which is why I'm asking here for some advice. Thanks.