Please help

Please, I need help. I feel I am I am finally becoming unable to cope.

 Actually I have often felt despair swamping me over the past 5 years since my husband sent an angry email threatened divorce unless I did certain things he wanted. He ended by telling me that "You are a good lay". That feel upsetting too. But things have always been hard to live with with him. He now curtly refuses to discuss the matter of his marital plans. I try to cope with the uncertainty.

 I am long term married to a guy who certainly has ADHD but goes undiagnosed of anything and thinks everything is either my fault or my responsibility to fix. I have often thought he trys to push me into a mother role. I am a kindly mother but I can't be a mother to my husband; that seems like incest to me emotionally though I have no problem helping with regard non intimate and impersonal matters.

My husband has always been very abusive and controlling and uses punishment and withholding a lot. He is constantly negative and blaming and is threatened if I try to talk things through or disagree, voice my needs or won't do what he wants. He says often that he is "head of the household" and has told me what to do. He now sleeps in another room and barely speaks to me. His anger is like a thunderclous with lightning around him. His face has always been so mean and angry around me that people can shrink and shudder when they notice. He controls everything and makes  poor financial decisions. He has motgaged the house and plays the sharemarket and spends without planning and unwisely.

I have been on a long growth curve involving much since I married him. I try to be assertive and not to be brought low by his dominance and destructiveness. I know I have learned a lot and am a lot more mature since I married him, not that I think I was ever really immature. I am still trying to improve. My biggest challenge is to find serenity and hope in my uncertain, unloving & toxic circumstances. I now feel i am losing this battle. 

We have been to counselling several times but he won't really participate and becomes very angry with me afterwards if I speak frankly. The last time we went was 5 years ago after I said I would divorce him if he didn't come. This was after he seemed to dissociate and attacked me physically & then shouted angrily that i was shouting at him when i was just quietly trying to get him to stop attacking (I couldn't escape). That counselling time he insisted I was crazy and everyone knew it. Now he refuses to go to counselling.

Please don't just say to go. There is too much at stake for that. But I think I can't go on as is.