-Cut back on non-academic stuff (ECs, research, downtime, etc.) to determine exactly how much time you need to put into courses to succeed. Once you've figured that out, you can begin to titrate the other stuff back.
-Always control everything that you can control. Most classes will have at least some small percentage of assignments that are basically softball points to increase your overall grade. Make sure you don't let any of these slip away or you'll be kicking yourself later. In the same vein, make sure that you are preparing to the maximum of your ability for every major determinant of your grade (e.g., exams). If the professor decides to give you some impossible test, that's their prerogative, but always do everything on your end to maximize the chances of getting the best grade possible.
-Study and review every day! If you don't understand something, go into office hours. I specifically arranged my schedule sophomore year to maximize the number of organic chemistry office hours I could attend. It's a very vertical class that's almost entirely dependent on understanding, so make sure you continue to stay on top of everything.
-You should basically be studying for the exams everyday by reviewing, attending office hours, doing all of the recommended questions, etc. That way, it won't feel overwhelming when you start really getting down to business before the exam.
Following these basic strategies, I never actually got a 4.0 for a semester but was usually in the 3.9ish range. It's doable as long as you put in the hours and don't overcommit yourself. Also, your GPA is fine right now. Try to improve it as best you can but I wouldn't "panic" at this point in time.
