They won’t leave me alone

We broke up months ago where I decided what’s best for me is to cut off all contact with them because I realised after we broke up how manipulative and controlling they were towards me. They won’t stop trying to contact me even though I’ve done almost anything to keep them from contacting me. Every time I hear something from them it’s like opening up a wound that was about to heal. I don’t think they are even aware of how toxic they are and I’m sure they think that they are in the right and I’m the bad guy here. They know exactly how to twist your words which scares me because we have mutual friends and I’m scared that they have told them their side of the story. I cannot do this anymore and I seriously think I need to go back to therapy because of them.