Having a constant feeling of nothingness is not something anyone wants to feel. For sure it does matter that you exist, and there are many people that would be devastated without you. You mention that you have tried a few things, but they are not working. Well one thing that you should try (if you have not already) is talking with your parents about this. They may not be able to immediately fix it, but they can provide you with some support. By giving you support, they can reassure you that you are valuable to them, and to this world. They are also going to be able to get you involved with some additional help, if need be. Additional help would include therapy, having someone that you can meet with on a regular basis and help you figure out where all these feelings are coming from.
Ultimately, what you are dealing with can get better. It is important to communicate with those around you, this way they can help you through this difficult time. Certainly you should not have to feel like this, nor should you have to deal with it alone. So please, go and talk with your parents about this. They love you, and want to be able to help you get past this. Another option is to go in and speak with your school counselor. They are also there to provide you with some support. So if you feel comfortable, then pop in and talk with them. We are here for you 24/7 as well, so please feel free to reach out to us when you need to.
Best,
Mandi, Counselor