Well first, take a deep breathe and relax. I'm in high school so I understand that you can get stressed easily, but what you could do is(and this is just what I do so you don't have to do this), check your grades and see what you need to raise up, then you can see what caused you to have a bad grade in the class, and then you can see what you need to do in that class that can help bring it up and then go from there.