If you often find yourself not believing yourself at everything, or you are thinking: I just don’t think I worth all these things, chances are you are hurting yourself emotionally and it is certainly not doing any good to you.
Why would it happen?
It is mostly because of an event in the past that triggers this emotion. For example, someone you love said/did someone to you that put yourself down. Or getting hurt by people emotionally because of what you did, and you took it to your heart.
Every time when you are thinking “I’m not worth it”, it is probably the result of a similar event in the past that triggered those emotion.
What you need to do?
Just by saying to yourself: I worth these things, without really believing it, is useless. But if someone is telling you why this is a problem, and also telling you how to overcome it, in a way that your mind can easily accept it, and get to believe in yourself again, would that be interested to you?