How to break up with an Ex.

I broke up with my boyfriend of seven years, two years ago. It was a chaotic break up where nothing was clear. Now, two years later he got in touch with me through text and tried to become friends. But I know that if I keep texting him, then I will never be able to move on. It’s been two years since our break up and I still carry a lot of baggage from that relationship. I have never stopped hurting and I know that it is just a matter of time before I go berserk and bring up the past with him. I need to stop all kinds of contact but he is making it hard by contacting my friends and social circle when I do so.
The reason we broke up was very unclear. He lost interest I think because he broke up with me the day his best friend confessed to him and soon they were dating. Though they only lasted for a fortnight and he did come back to me, I couldn’t trust him. I know that some part of me still loves him and I am desperate to not make the same mistake.