I am a SAHM and though it drives me insane some days, I wouldn't give it up. I have had both of my kids in what, where I live, is called "parents day out", usually run by churches, though not religious based or preachy (well, mine isn't) and is 2 days a week from 9-2. My son goes Tues/Thurs, but others go Mon/Wed. You might check into that in order to allow you 1) a break and 2) opportunity to work from home or look into those opportunities.
Also, I found that once my oldest started school....that was when I really felt glad to be a stay-at-home-parent. The days and weeks got faster as the hamster wheel of life speeds up. Every day you are dealing with the get to school/pick up from school. Homework. Projects due. Activities/events at school. Volunteer opportunities/needs at school.
School ends at 3pm, the kid wants downtime to play because they've been told to sit and be still and be quiet all day long. Then, you have to get homework done and then there's dinner and oh yeah, it's bath night and then they want a story or a game with Dad and wow, now it's bedtime because you have to get up super early for school tomorrow. Hamster wheel.
Then, there are the sports your kid all of a sudden wants to be a part of because it's baseball season or soccer or basketball and his/her school friends are playing. Oh, and they are talking about scouts at school and he/she wants to do that too. What's that? They are starting chess club? And then birthday parties on the weekends because your kid now has 20-25 classmates and invitations abound.
At don't forget the petrie dish that school is (or daycare as well) and how thankful I am that I don't have to call into work when my kids comes down with strep or stomach bug that is going around school.
I'm not trying to sell being a stay-at-home-parent, it's not something everyone can or wants to do. I'm just saying that the "waiting for your kid to start school" is not all it's cracked up to be and is usually a harder time that you imagine. I had no idea and thought it would be easier. I was wrong. It's a harder/faster/more involved life than toddler/preschool years ever was, in my opinion. In fact, I'm thinking about homeschooling simply so we can get some time back.