Need to stop feeling so numb

My husband was diagnosed with severe ADD by 2 Psychiatrists and 1 Clinical Psychologist. He refuses to take medication or go to therapy and said that his personality is such that if a therapist tells him to do something, he will do the opposite. We have two children in elementary school. I am so numb that I can't even cry any more. Crying used to help relieve some of the tension. I struggle with this daily. He is becoming more and more mean. He is using off limits accusations and words in front of our children if I even bring up the subject that he needs help. The children know he has add and refuses to get help. I know I should start over, but I'm so tired and run down after being with him for 17 years. As ridiculous as this sounds, I know what I get with him. He zones out completely during conversations with me, our children and other people. He was on Vivanse for awile and it helped a little, but then when he started therapy 4 years ago, he accused me of digging him into a hole. The therapist corrected him and said that he was digging his own hole and that only he could dig himself out and being verbally abusive and taking away my dignity on purpose wasn't going to help him. He decided he didn't need therapy or his medication any more and it's been even more hellish.  His compulsiveness is unbelievable. I simply don't know where to turn. We don't speak for weeks sometimes. I have so much anger and resentment that I don't want to put any more effort, energy or love towards this man who I deeply and truly despise. He makes my skin crawl and my stomach nauseous. My family doesn't want to hear about it. My friends think I should leave him. I've been a stay at home mom and I feel so stuck. Like no one understands what it's like or the extreme loneliness,  when I have so many ideas, fun and love to give. I give it to my children and are sacrificing for them. I do that happily, but our fights are so intense that the kids do end up hearing them and are devastated. I know what I need to do, but I'm scared.