You HAVE to make a stand OP.
By sitting back and taking this you are adding to it.
I'm not blaming you for this, but if you don't stop this right now, who is going to.
You clearly love your family. By allowing them to treat you like this, to do nothing to help, to allow your H and the DC to abuse your position, pay you no respect you are creating monsters.
You HAVE to do whatever it takes to be heard. SCREAM, SHOUT, whatever it takes.
Strike, don't pick up after them.
Tell H to keep quiet unless he is going to back you up 100%
If he's not going to keep quiet OR back you up, tell him his presence is detrimental to the development of your family and you would all be better off without him. BLUFF IT, look as if you really mean it.
If you don't take responsibility for your own happiness and self-fulfillment, who will? You'll get more and more worn down, and either snap or being prone to an affair. Which would damage your relationship/family, possibly beyond repair.
Draw a line NOW. Take a stand.