Yet another existencial crisis

I've been trying to study Calculus IV today, but I haven't been into the mood for that. Actually, I think I can't been much into the mood for many things, really. I got this feeling that all of my efforts are worthless. And it makes me wonder what my existence is all about. To do all the worthless things? To survive? I learned how to get rid of those those thoughts, making myself busy and not thinking about it. It won't ease my silenced inner self, tho. I can't feel I grow up as a person who works for making our beautiful planet a better place to live, but a toolmaker, who makes tools so others can use and change world at their will, since they got the power to do so.

I'm sure I'm not the first and won't be the last to reflect about it, but this kind of reflection came in such an early stage in my life, when I still got absolutely nothing in return to the society. The only thing I got are questions that nobody can answer, but that I should find it myself.