I don't know what makes you think you are evil. Though I don't think it is possible for someone to not be worthy of therapy, it is possibly for someone to not be ready to do the work that therapy involves. Not to be answered on here per say but would you be able/willing to write down the reasons you think you are evil and write down the definition of evil and bring it in to therapy? If you choose to do this try to stick to facts. While it could be debatable whether you are evil or not, feeling like you are evil must be a horrible feeling for you to have. I hope you feel better soon.