is it dumb to look for a new clinical job now

I am currently working as a CNA at a completely understaffed and run-down rehab nursing home. Thankfully, this job is PRN, so I have some control over my schedule, but I dread going into work. It's depressing seeing the geriatric patients not getting proper care, and I try my best, but having 13 patients on a rehab floor is recipe for disaster. I want to desperately start job hunting, but I am taking the MCAT in February and am currently a student, so I really do not have much free time. I want to focus on my MCAT, but I want to also change jobs. The good thing with being PRN is that I can choose my hours, although the staffing coordinator tries to get me to work ALL the time. Do I look for a new job now? Do I wait until after my MCAT and suck it up?