I broke up with my boyfriend of a year and a half

I broke up with my boyfriend about a month ago after being with him for a year and a half. We met at school in health class and we became best friends so easily. Our relationship was amazing until it wasn't. He always thought that everything was perfect and for a long time it was. But it got harder for me to open up to him and I let my past relationships dictate my behavior. Even though I know he's the best I could ever possibly have had, when I broke up with him I told him that I didn't love him. Which is wildly untrue. I let my self doubt drive me away from him. I want to be back with him so badly and we've talked about it. He still loves me but he's enjoying being single. But now that I'm opening up to him it's making it harder for him. I cry constantly thinking about him and how we used to be and how bad I want that back. Does anyone have any advice on how to ease the pain??