#1- If you sent your children to private school you would still pay taxes to support public schools. If you send your children to public school and you are unhappy with it you still pay taxes. You don't get the money back if you decide your kids aren't getting a good education. If you don't have children you still pay taxes to support the schools. That is just the way it is. Our tax money goes to support a lot of things that don't personally benefit our family at this time.
#2- Did you and your dh attend school or were you homeschooled? Dh and I were both ps educated and still never fit the mainstream mold. School did not make us happy little cogs. I prefer my dd to be who she is and be happy and confident about it rather than being fake or feeling bad that she did not fit in.
Dd has always been homeschooled and is not shunned by ps kids we know because she is homeschooled. She doesn't stick out that much. She isn't dressing like a pilgrim or sitting around reading dry textbooks while other kids are playing. She likes the same music, movies, animals, and video games just like many other kids.
#3- You can get to know other homeschool families and join a support group. You can hire a babysitter for the kids or a caregiver for your dh if you need a break. Look for ways you can line up some support now.
Things are different as your kids get older. They won't always need you to be on top of them or involved in their activities. They can learn to help around the house. They can spend time at a friend's house.
The amount of time and energy you spend actively homeschooling can vary depending on your choices. We are pretty relaxed homeschoolers. Dd is 12 and we maybe spend 2-3 hours per day on work. Dd does some work independently but most we do together. The rest of the day is free time. She is really good at entertaining herself. We will be working on leaving her home alone sometimes now that she is 12 years old but dh and I can also watch a movie together or just tell her we need time alone and she does her own thing for awhile.
Basically it sounds like none of this is about doing what is best for the kids or about how you feel or homeschooling in general.
Your dh doesn't want the kids around or to share you with them so much.
Maybe address those feelings instead of the reasons he gave.
Maybe ask him to give homeschooling a trial and agree to re-assess at the end of the year.
Maybe agree to K with the understanding that you will hs starting first grade.