Shitty people

Might be immature about this but, I met this person who manipulated me so much and I didn't even realize it till now but now that I do I'm so scared of them. But I was so close to them before I slowly pushed them away, so they still talk to me since I didn't throw them off completely. I always try to make them stop talking to me but they won't stop trying to get friendly with me, it gives me anxiety. What if one day I decide to be friends with them aswell? It'll all go back to like it was before. They were the reason my mental state went to shit and now I'm not doing as great as I was before I met them. They were the reason I'm suicidal.