Yes Let him Go, it is the only way that you might get him back. Think like you are holding a bar of soap the tighter you squeeze the faster it slips away.
Get the DR book and read it. Get out and GAL. DETACH. Believe none of what he says and half of what he does. Have NO EXPECTATIONS. Take care of yourself, breathe, eat, sleep, exercise.
You are on moderation right now on the forum. SO post in small frequent posts until you get off of it.