Is this man stalking me or just harassing me?

36 (I think) year old man named Eric who I met when I was 17 (he was 32). He drove me down to Chicago to go see my ex. This was 4 years ago.

For obvious reasons, I don’t want to talk to Eric.

However, he has messaged me on many different accounts that I own, using many different accounts he owns including fake Facebook profiles with fake names, and using his YouTube branded accounts.

He keeps not understanding why I do not want to talk to him. I block him all the time but that never works, obviously.

He always comes back either days/weeks/or months later with a new account.

What do I do? Restraining order, call the police? It has been 4 years of trying to contact me.