You want to be a dermatologist, which means you want to go to med school. For med school, you need at least 1 year of physics with lab, maybe even more. On the MCAT (which you need to take to apply to med school) there is a physical science section, which probably encompasses physics. You cannot get around the subject, and I’m sure college physics would be more bearable if you had previous exposure.
You can take anatomy and psych in college. I have heard of doctors who take anatomy for the first time in med school (there is nothing wrong with that. First year med school anatomy classes are designed for people who have not studied anatomy before). If you have time for those extra classes in high school, go for it. Don’t substitute any of the core sciences (bio, chem, physics) with anything less rigorous, it’ll only be a disadvantage. Most kids complete the bio/chem/physics sequence and take an extra year doing AP-bio/chem/physics or another science like AP psych/environmental.