Ariel Gore says in one of her books, and I'm paraphrasing here, if you have to choose between spending money on a therapist or spending money on a housekeeper, choose the housekeeper.
I can already hear it, though: "Wait, you're a stay-at-home mom, why on earth would you need a housekeeper?" I'm lucky, if you want to call it that. I have had fibromyalgia and then a heart condition through much of my stay-at-home career, so I have an "excuse." But I heartily recommend housekeeping help for healthy homemakers as well. If you have the money, it's very well spent.
Never forget that staying home is a 24/7 job. You're at this with very few breaks every single day, usually for years. If you hire someone to take some of that load off of you for a couple of hours a month, or better, a couple of hours a week, that's hardly an indulgence. Author Kathy Fitzgerald Sherman says the average American stay-at-home spends 39 hours a week on housekeeping--not counting child care. (Sherman's book: "A Housekeeper is Cheaper Than a Divorce"!)
At the very least, consider hiring help quarterly for big cleaning jobs: Washing the walls, the outside windows--all the heavy-duty cleaning that doesn't need doing weekly but that really can wear you out.
If your partner complains, tell him he can either give you that break himself or he can hire it out. Give him a couple of bouts of cleaning the oven, the fridge or the windows and he'll be reaching for the classifieds himself. That's not an indictment of guys; that's just reality. He's tired from working all week outside the home as the breadwinner. But you're potentially even more tired from constantly being on duty.
Too often, the last two priorities on our to-do lists are our relationships, followed by ourselves. Free up some of that energy for yourself, and for your partner. Hire some help around the house.