In that case, I think I'd sit down with DH and tell him how it makes you feel when he is always asking what you're doing with the money.  Tell him when he does that you don't feel like you're in a partnership with him.  Let him know that you gave up a significant amount of your income to make the household run smoothly, and you don't appreciate having to account for everything you spend or save.  And if he doesn't understand or keeps it up, go back to work full time.  I agree that you need to have something for yourself if the marriage goes south.  That's why it's risky for women to stay at home with someone else's kids, reducing their current and quite possibly future income.

Getting the younger kids off to school daily? That's Dad's responsibility.  How did that even work?  High school generally starts earlier.  Sounds like he dumped them off on the older kid and  ow he's dumping them off on you,  unless you agreed to this and he provides complete financial support for you in exchange for assuming role of homemaker.  I'm not saying there would be anything wrong with that if that's what you want and you are provided for including a good insurance policy on him for your and his kids' benefit,  and an IRA for you that he contributes to.

"Gave it all to BM & the skids"

Do you mean voluntarily.. or part of a settlement agreement and CO with his EX?  As in, were the costs court prescribed for the most part?... aside from nominal gifts at holidays etc...?  If it was part of their divorce agreement.. it is not like he really had a super big choice in paying that.. many men end up with a short stick end in these situations.

But... really back to the here and now and your current situation.  You and your DH do have a difference in income currently.. and would have even if you were making 2x what you do now (your prior income).  I am assuming you moved into his home.. and I am assuming the cost of owning that home is probably more than the situation you had before.  Have you thought about sitting down with him and really hashing out the costs?  What is your fair "share" of the household expenses... including groceries.. utilities... etc?  You are one person.. they are 4 so you should theoretically be responsible for 1/5 of the costs.  So, what is that number?  is it more or less than you are spending now from your own funds for groceries etc?  What is the value that is saved by you staying home?  30K... seems to be what you are losing.. could your role with the kids be replaced for less than that?  His kids seem to be old enough to be more self sufficient than they are currently behaving.. perhaps dad should be more demanding of the older kids.. and make them be responsible for their younger sibling?  Maybe even to the tune of a little bit of financial payment to them for doing the responsiblity.. Then you could go back to work.. earn your former amount of pay and then you would contribute your "share" of costs... for things each of you would pay for.. you reimburse him for 1/5 of what he spends.. he reimburses you for 4/5 of what you spend.  Any money over and above that belong to each of you... if you want to buy his kids a present for birthday/christmas.. sure, that would be nice.. but it is not going to count as a gift from HIM.. he needs to buy his kids what HE wants them to have.

I agree with others that think the stepparent staying home and sidetracking their career for the children of the new spouse is a pothole filled road.  In your case, you have no bio kids in the mix.. the kids involved are not very young.. and could certainly be expected to manage on their own.  He just needs to set higher expectations on all of them.. unless there are disabilities that prevent the responsiblity.. he would be doing them a great favor to teach them more responsibility.