My love, you are not worthless. No one is worthless, you know why?
Because we are individuals that have the same capacity to create wonderful things in this world. Look at you, all the incredible things that you can do. All the lives that you can change and all the things that you can achieve. Embrace yourself, look at who you are. You are a human that is unique and that brings it's own imprint (path) into this world.
You have so much to give to this world and I know that you are already giving a part of yourself to this world. Acknowledge what you have accomplish, don't think that far. Anything simple is an accomplishment. Have you ever make an individual smile? Have you make someone feel loved? Have you ever helped anyone? Have you given a compliment? Be proud of what you have done.
Give lots and lots of love to yourself. After all, you are a human being that is unique. Compliment yourself over things that you are proud of yourself. Even when something goes wrong, remember that you are allowed to make mistakes. There is nothing wrong. You are not a failure. Remember that you are going to be okay. Use your experiences to make yourself stronger and better, don't tear yourself down because of that.