There's a lot of things in life that we do that we don't always enjoy. The fact that you're asking this on an academy forum, gives the implication that you are also interested in the air force academy. So while it is true that everyone must find balance in their lives, true sacrifice is what makes certain things worth it.
Time is finite. That means while you're spending time doing whatever it is you're doing, it would be a waste of that time if you don't give it your all. So doing a mediocre job at either doesn't seem like an option. The balance that you're looking for, must also be balanced with the rest of your time. With athletics, volunteer time, extra curricular, clubs, your academics, etc...
Only you can decide if you don't have the time or passion to do what you're doing. The academy expects a well balanced cadet. But that well balanced cadet also has to stand above all the other competition. 12,750+/- applicants. 1170+/- accepted and entered the academy. Where would you stand in that list? I've seen 4.0gpa/33+ACT/2200+SAT applicants get turned down from the academy because academics was all they had. Matter of fact, I've seen similar resumes get turned down from many prestigious Universities because they too want "Well rounded" individuals. I've also seen 3.6gpa/27ACT/1900SAT receive appointments because they had all IB/AP classes, were class officers, were involved in sports, did volunteer time, was involved in clubs, did summer activities, etc...
Bottom line is: Only you can tell if you are doing too much. Only you can decide if you need to give up something, or.......... simply work harder. Without all the hoorah lecture, if you have leadership, athletics, volunteering, extra curricular, clubs, etc... and a full resume; then dropping one activity will most likely not be an issue. But only you can decide that. There is no "Magic Checklist" that exists that says: "Fill the following squares and you automatically receive an academy appointment". The academy simply looks at your entire application; determines if you challenged yourself to a reasonable extent (Academically, socially, and physically); and if you succeeded in those challenges. Then, they grade you on it. If your grade is higher than your competition, then you receive an appointment. Don't ask who your competition is; that is different for each applicant. (There's many different appointment sources).
So; sit down, reflect on where you are and what you want to be doing in 2,4,6,8+ years from now, and determine what you'll do to achieve that. Best of luck to you. Mike......