I am on maternity leave with my first child, who's nearly 9 weeks old. It is bloody relentless and I would love 8 hours uninterrupted sleep and I'm v sick of constant laundry, but people who say "being a mum is the hardest job in the world" obviously haven't worked a high-stress job outside the home. I am currently on leave from my job as sole lawyer for a medium sized company and it was far more stressful, even with regular full night's pre-DS.
At least now my time is my own, I'm the boss (supposedly) of DS, I don't have deadline pressures, high stakes advice that could have financial or commercial ramfiications, office politics to negotiate.
This morning we got up at 6.30am after a feed at 2.30 am and resettling at 5.50am,I fed DS, expressed, we went for a walk to the park with the dog & I got a cofee, I've done a few chores, played with him on his playmat, fed, now I'm mumsnetting & watching the cricket. Later I might take him to the beach (it's summer here) and visit my mum.
If I was at work I'd be shut in my office on a lovely summer day, the dog wouldn't have been walked til this evening... and all the chores would still need doing after work! Assuming your child is in good health and you're not under undue financial pressure, there's no way you can compare the "stress" of SAHM-ing to the stress of a pressurised career.