Should I drop some courses?

I'm an international transfer student at a top30 school in United States. I've just finished my first year(junior standing) and my major is financial math and econ. Recently I felt that i'm taking too many classes, and i 'm too nervous of losing GPA(right now my GPA is 3.9+) so i really can't do much other than taking care of these classes(you know theoretical math are killers and median of econ courses are all B). I'm feeling like i'm not on the right track so i'm thinking of drop some courses so i will just achieve one major are just don't care about GPA but focus on networking and preparing for interviews and i would like to listen to you guys' opinion. Anything relevant would be appreciated.