Encouragement/Advice please

I have been a CMA for 3 months. There are many things I enjoy about my job, but I recently got negative feedback about my attitude. This surprised me as I thought I was exhibiting a good attitude at work. I can be quiet and there were times when I felt uneasy about a lack of structure, but I thought working hard and keeping my head down would speak for itself. I feel uneasy about this feedback and get nervous about going into work. I'm stuck at a crossroads of sorts: I would like to tell my supervisor I want to explore other departments, but I am not entirely ready to leave my current department. I am afraid of how she will react to this, but I don't have a lot of confidence that things will change in the long run and I will leave the job anyway eventually. OR 2. I could stick it out and possibly learn more. I feel it might look bad to leave a job after 3 months even if I feel I am not thriving.
Is it smart to tell my supervisor I want to explore other options? Has anyone else had this kind of experience? I go back and forth on what I should do. If there is a personality conflict I don't know what I can do about that. Seems like some people may have already made their mind up about me and I don't want to waste time trying to change people when I can focus on patients.