revenge porn HELP

Emily
so. my ex of nearly a month who i was with for nearly 6 months has threatened me with videos of us having sex. i've had to block him on everything. he has found an old twitter account of mine that used to be a fan account for one direction. 
when we split up i was adamant to him that they must be deleted. he deleted them in front of my eyes. he must've had them elsewhere other than his camera roll. 
this probably makes no sense. i can't make much sense of this myself. i'm just putting my thoughts onto a page. i'm 17 and in england this would be child pornography. my mum was opposed to us even having sex. i wasn't allowed to go to his house once she found out we were having sex. i'm so upset. this relationship was tiresome and emotionally abusive. i'm just baffled as what to do