That sounds like a direct threat, that if you behave, he won’t come for you. How absolutely terrifying.
Getting divorced from an abuser isn’t the same as separating from someone normal. Rights of Women has loads of useful advice and a good helpline. The helpline is usually busy, so be prepared and keep trying. Also your local Women’s Aid may have a solicitor attached, and Citizen’s Advice is a helpful resource as well. Bit by bit you’ll find your freedom. It’s a very difficult and chaotic time.