Final practicum choice

Hi, I'm in the process of choosing a final practicum and am interested in emergency or intensive care, but I'm not sure if these are logical choices for me or not.

Some things about me: I love physiology and research. I'm also passionate about psychology, although I think I would benefit most from a placement that allows me to use my skills. I've enjoyed clinicals such as Cardiac that incorporate more physiology. I did not enjoy med surg so much as this was more about procedural knowledge (types of surgery, etc) and didn't fulfill my interest in physio as much. Unfortunately, I feel that I should be an expert in everything, which makes it hard when I go to do a skill for the first time and feel so amateurish...I have felt a huge lack of confidence and a huge fear in caring for patients. However, I've been gaining more and more confidence on the cardiac unit and feel that with time I will be a confident nurse. I would love to do my practicum in the ER but fear that I won't be able to think on my feet? Perhaps I will panic with the instability of patients?However, my GPA is > 3.7, and I don't think I should run from an ER experience because of "fear." The ER would probably be very rewarding! Unfortunately, I have not had the time to work as an undergrad with family commitments and other things going on in my life.

Based on my strengths and weaknesses, do you think an ER or ICU practicum makes sense? Or should I choose something with a slower pace?