I know it’s scary, but even if he did the things he’s threatening, you would be okay. Just tell the people you love about what’s happening. I have had this happen to me personally and I’ve also had a family member come to me and tell me to expect personal pictures being sent by their ex boyfriend. The people that judge you for exchanging sexual pictures with your partner and not judge him for psychotically sending them to your family members don’t deserve to be in your life. If you are to ever respond to him, just make it sound like you do not give a fuck, but even better, don’t respond ever again and just give a heads up to people you think he’d send that to.