As per above. You need to work on your core beliefs about yourself. CBT is helping me with this but there are other forms of therapy too.

You say you are worthless. Do you know anyone who is worthless? Likely not. You probably wouldn't put yourself in the same category as sociopaths and that of Hitler, etc. If you were to make a scale of worthless on one end and worthwhile on the other end you may be surprised then where you think you fit in.