How do I tell him "I just want us to be friends and nothing more?"?

Hi everyone! I'm 17 and a senior in high school. I have a friend that I've known since I was in 8th grade. We stopped talking in my sophomore year until about a year later when I reached out to him. We've basically talked every day since then. We've dated before, most recently, in the beginning of my sophomore year. About a month ago, we agreed to be 'friends with benefits.' I saw him 3 weeks ago and he was really getting on my nerves, trying to make me kiss him(which I didn't want). A week ago, I told him that I didn't want to do friends with benefits anymore and I wanted to be just friends with him. He took that as I didn't ever want to talk to him again, which was not my intention at all!

He's been such a great friend to me and I don't want to lose him, but I just want to be friends. So my question is, how do I tell him that I did still want to talk to him, but I just wanted to be friends?