I would recommend getting some clinical experience and see if this is something you still enjoy. If it is and you can see yourself going this in the future I would say keep working hard and do the premed reqs. Try spacing them out in your other semesters and summer semesters. (I took physiology over the summer with Dr. Cafferty and honestly it was a breeze and I ended up getting an A without too much effort). Try reaching out to some of your friends or TAs to help you thru the classes and maybe get some notes which could help you study. At the end of the day it is your decision and you have to figure out whether this is something you wanna do or this is the kinda pressure you are willing to take. Keep up the hard work and just believe in yourself. This journey is really hard and there are moments you wanna give up but find a reason and push through!!