May I suggest you try writing a song from your own experiences and feelings. It does have to be anything spectular. It can be a trip to zoo as a kid or a bad date. Write what you are and not what you think you or others think you should be. Be yourself and write about yourself.
I am curious. What kind of music do you write? I think you may have some natural talent and you need to write what you feel and try to happy. Depression is a terrible thing and what this world needs is to cheer up.
Don't cut yourself down. There's enough people full of eny of your talents and will do all the cutting for you.
Keep trying. Don't give up. And be happy!