I can’t let him go

From the beginning he said we were just dating but he didn’t want anything serious. We spent time together, we texted and talked constantly. It was some of the best days of my life. He agreed. Then he just stopped. He said he felt drained by life and work. Said it wasn’t me. The texts stopped. I told him I would be here for him and thought time would ease what he was going through. It didn’t. And I’m just here so alone missing him.