I think it is unfortunately pretty easy to see that the M you are in is not good for anyone right now. It isn't good for you, it doesn't seem to be good for H, and as a result it really can't be good for the kids.
It seems you are still operating from fear -- fear that you will leave is making you avoid dealing with the sitch. And, I know you know that operating from fear isn't good for anyone.
I still encourage you to go to a lawyer and figure out your legal position. Knowledge is power. If you know you will be OK if you D, then you might just find the strength and courage to really set down the hard boundaries in your R that need to be set if there is to be any chance of saving the M.
I know you don't want to go to a lawyer because you are afraid you will then immediately leave the M. Again, operating from fear is not healthy.
Learn your options, make informed choices, and get ready to change your life one way or another. To motivate yourself, think about talking to your children 20 years from now about the choices you made in their childhood. Trying to save your M for a long time makes sense. Continuing after a certain point, when you can continue only by avoiding the truth about your sitch, your feelings, your options; when you can continue only in a way that is doing damage to yourself and does not seem good for your H; when you are modelling a sad way of life for your children DOES NOT make sense.
So, quit avoiding, confront the truth. See how it empowers you. See how your knowledge may free you to actually save your M or free you to leave it.
