As long as you have the view that leaving is not an option, he will have the upper hand in the situation and there is NOTHING you can do to change his mind.
Speaking as a male myself, your partner (I can't call him a husband because he doesn't live up to the name) is getting to have his cake and eat it too. Stop giving him flour!
You have two boys that need a much better role model than the partner you are married to. NowWhat is correct about this.
I have to agree with many of the others who have answered you. I think your situation has gone beyond counseling. A divorce would clear the air and give him a reality check. And if you feel tempted (as I suspect you might) to remarry this guy later on BE SURE THAT YOU GET AN IRON CLAD PRENUPTIAL AGREEMENT BEFORE the I DOs are done.
I know it's rough and it's painful. I have been down this same road with my first wife (only it wasn't just one with her) and there were three boys (two of which were really mine). Like you, I tried very hard to make it work "if for no other reason than the sake of the kids". Then I finally realized that was the very reason that I had to say good-bye to her.