how to confront with setbacks?

In dealing with academic failures, I admit that I feel bad when my grades are affected by the so many tasks I chose to engage in. Being part of various organization in the college made me vulnerable in setting aside my academic performance at times. But when I see the result of that particular action and I see my grades getting lower, I definitely pinch myself a bit and refresh my priorities. We are at school to learn and prioritize our studies. Indeed, there will be times when we will fail and feel the pressure of school. I guess we just have to have a clear goal. We need to set priorities and gauge things according to their importance. Regarding personal relationships. I sure can't please everybody, and also, I am not easy to please. At school, I really can't shut my mouth when I see someone doing something wrong. This is why I can say that most of the time, I am misunderstood. What do i do when I feel people talk behind my back or raise eyebrows everytime I pass them? I just, don't care! I just think that I am not at school to please everybody and be a popular nice-nice girl. I just need true friends who share the same goals with me, and with these few true friends that I have, I know I'll be fine.