I think if you are still with him, it's because your self-esteem must be really low. Probably you are afraid of sending him to hell, because you think you won't find anyone else? please, trust yourself, believe that there are many nice guys out there in the world, and you might be missing the opportunity of being with one of them, because you are stuck in this dead relationship.
Like you said, you already know the answer: leave him. Time to say goodbye! You know what might happen, after you separate, he will think about it and maybe will start to give you proper value, so, give yourself a chance to be happy and if he notices later what he has lost, and you still feel something, you can go back together... but now, it's really not meant to.