If you feel that this has become a real problem for you then I think you should delete your characters. I think it would be best for you to do it yourself, the process of personally letting go will feel good. "But I just can't bring myself to do it." If you're having this problem then I'll explain what I do, maybe it will help. Whenever I want to delete something that I objectively know I don't need or want but something is holding me back I just put my finger on the button, clear my mind of any thoughts, and act. Just clear your mind and act.