Often times, we feel useless because we don't think we contribute anything to the world around us. While that's not true--everyone is important in some way for whatever reason, and you deserve to be here as much as the stars in the sky do and the water in the ocean does--that doesn't make it easy to erase this feeling of inadequacy. The solution? Raising your self-esteem.
Start figuring out the person you want to be. You don't already have to know who you are. The point is, figure out what you think makes up your ideal self and aim for it. Do you want to speak a new language? Make a goal to learn one. Find language learning services (I suggest Duolingo) and try to find a way where you can immerse yourself in the culture of the language (like if you want to learn Japanese, try reading lots of manga and watching anime). Do you want a job (or a better one)? Start looking. Update and spice up your resume, save up money and look for grants and scholarships if you need to go back to school. Do you want to travel somewhere? Start making plans and saving money.
Make in-depth, thought out, well-developed goals. Start with a main goal, and then create the steps you need to achieve it, making small goals off of those. If you want to feel like you're doing something important, you need to figure out what is important to you and how you want to affect the world. What will it take to make you feel like you matter? Designing fashion? Making art or writing stories and posting it on the internet? Reading a certain number of books a day? Whatever has made you feel accomplished in the past, utilize that now and decide how you're going to take away these feelings and boost your self-esteem.
