Letting Go Feels Impossible—What Should I Do?

There is a guy (43m) I want to walk away from when I’m with him, but once I (26f) do, I start missing him. Not because he’s good to me, but because I don’t know how to explain this feeling. I know he may not be the right guy, yet I still can’t let go. What should I do? How can I forget him?

When you miss someone who has brought you pain, what should you do? I know this sounds contradictory, and I don’t even know how to explain it…