Dump all his texts on a website, adding his name and your explanations, post, and send him a link. Tell him that if he distributes your pictures, you will immediately send a link to your website to everyone around HIM. Do that if you indeed know the email addresses of his connections. And, that does not substitute for contacting the police and/or a lawyer. You can supplement with it, but you need to drop your hopes to resolve it COMPLETELY quietly.

You need to learn to use the language that would not make you feel embarrassed when you contact the police. You are going to the police to assert your rights and obtain protection from coercion/blackmailing/harassment/defamation and these are the terms that you should use.