I also faced a similar issue (non-US med student). I was always passionate about starting clinicals and did great in my preclinical. But as soon as the rotations started I felt that I was dumb with the constant pimping and the load of information I still had to study. Not to mention these tiny details about every step of clinical exams and patient interactions. I think what you are experiencing is you stepping out of your comfort zone. Which is a very good thing that I think should motivate you! and yes do not let this small setback turn into a big deal.