Try to figure out what's the issue. 1st, be honest with yourself. Did you give it 100% of your effort? 2nd, if not, try to find strategies to be more efficient, talk to your profs in office hours (treat them like class hours), talk to upperclassmen that have succeeded in class. 3rd, take responsibility and don't blame others (for better or worse. If you get 90, that was all you bro!)
I am against considering dropping the class until the last possible minute. It's too easy to throw in the towel and take an easy escape route which could ultimately be harder. Until that time, stress test yourself and figure out how much work you can handle, what works, what doesn't, etc.