is my ex blackmailing? what can i do legally?

[adgomez98]

This is very personal for me.
When I was 19 I did personal videos with my ex boyfriend. I of course regret it now, being i was only 19 and naive. I'm 23 now.
Anyway, I still keep contact with him. Through texts messages we were talking and he brought up the videos. It led to him saying if I should perform oral sex to him to prevent him from showing the videos to people or posting them online. I lied and said I'll do it to buy time. I of course don't want to do it and i feel so horrible for even doing the videos in the first place.What can i do legally? Is this blackmail? Sexual haressment? I don't whether i should tell him what i can do legally first or pursue what i can do legally without telling him. Can he post them online without my consent? any other tips would be helpful.