A nanny sounds like a brilliant solution for you, as it would likely save money *and* remove some of the things from your plate.
That said, I think that sitting down with your DH and proposing the that you take a sabbatical is also a great approach, but needs to be done carefully and thoughtfully. You should hash out a plan with your DH that includes lots of specifics. What are you willing to sacrifice to make this happen? Again, be as specific as possible. Have a spreadsheet with all the savings (childcare, your commute costs minus perhaps a bit for more chore running, expensive work clothes and dry cleaning if appropriate, etc.) but also consider less obvious areas of savings. Do you current eat out regularly or buy prepared foods for the time savings? If so, then commit to cooking dinner 28 of 30 nights a month (if you are willing to do that, or whatever number is appropriate) and estimate those savings. Likewise making lunches for you and the kids and your DH, instead of eating out or buying school lunches. Also include savings from any items you currently hire out (cleaning, laundry, anything), but if you do that, you need to be prepared to actually take on those things. That is going to require a lot of honest introspection. Are you willing to add more of the domestic stuff to your responsibilities, in exchange for shedding with job? Also, consider what else you are willing to sacrifice. Can you put in the effort to thrift all the kids' clothes, and commit to slashing that budget by 50%? Buying them fewer expensive toys, and a 20% savings on that budget? Thrifting your own wardrobe, and cutting down it's size, for another 20% savings on that line item? Showing that you are willing to sacrifice things to make this work will probably go a long way, so consider what splurges you current have that you are willing to cut. Since you are the one who wants the change, it's probably going to be a much easier sell if you shoulder more of the obvious sacrifices. If you can't give up your weakness for shoes (as a random example) or your need for your kiddos to be dresses in new, not-cheap clothes, then the message you are sending is that while you say you want this, it actually means less to you than owning a lot of pretty shoes. So look at every option, see what you are willing to give (without expecting a matching compromise on his side, since his compromise is going to hopefully be agreeing to go to a single income), and propose that.
If he's still unwilling to bend, if it is truly bad, I'd likely then be ready for a bit of a come to Jesus conversation. Here's the spreadsheet I've made with everything I do outside work 9assuming you work and commute similar hours) and here's what I've put together for what you do. Feel free to add anything I've forgotten. Okay, it looks like I do 15 hours more per week of stuff for our family. What 7 hours are you willing to take on? Because I can't keep up this pace. And I *won't* keep up this pace. I need help and since you aren't open to me not working, the only other possible option is for you to do more. (This approach does have some dangers, of course.) Be ready to examine the details of your chores, and be open to efficiencies. If you are spending 4 hours a week grocery shopping because you go to 5 different stores, maybe that changes. Or if you make lunches for the kids in which there are rice sculptures in the shape of tigers, that's not fair to count toward minimum requirements to keep the house running. If you prefer the house to be pristine, again, that's a personal choice. Those things can be cut, and should be, if you are at your wits end with this.
And I think it is fair for your DH to want some sort of escape hatch if they plan isn't really working. So maybe you commit to do this for 18 months, and then reassess. Of course during those 18 months you'll get together frequently and talk about what is and is not working, but I'd go in to this telling my DH that if, after 18 months something about this was still terribly awful to him, then you are willing to explore getting back in to the workplace. This way, you are only asking him to commit to a trial period, not to an irrevocable action that he fears could be a giant mistake.