How do you define yourself? Okay, maybe all of you at least can decribe yourself but do you know the purpose of your life?
This is a subjective matter because everyone has different opinion about the purpose. But how to make ourselves towards that purpose? That is the most important thing.
By the way, nobody in the world can be called useless because they know what they capable to do or not. Unfortunately, many of them fall into that categories because they only think that purpose but never do something to achieve it.
In conclusion, you should do something no matter what happened. It is because we live for short time. By the way, use the precious time wisely.