Hello, I am a solicitor with 20 years experience. I will try to help you with this.
If the extent of what these people have done is what you have said they have done then this not a crime and the police will not be able to help. Although it is obviously unpleasant having people say untrue and unpleasant things about you I don't think that there is any practical legal remedy for you. In theory you may have an action in defamation but the costs of those sorts of proceedings are ridiculous. I think you are in one of those areas where you are the victim of unpleasant behaviour but on what you have described it is not so bad that either the police or the civil courts will be able to help you.