Hacked Iphone With screen recordings

This is the 2nd time around. It happened last year that I received a yahoo email threatening me that he hacked my phone and then screen recording something like porns and browsing stuffs and saved in my phone photos. I immediately changed my apple id password. Today, no email but a 1hr and 59mins screen recording again was saved in my phone from 1am-3am which I am not aware of. How can i prevent this to happen. I changed again my apple id. Not sure why is this happening to me. Anyone can help me please.