You have a range of emotions when you withdraw your child three weeks before school ends and start to homeschool. I know. I did the same thing last year with ds7 (2e pg) when he was in kindergarten at a gifted, Montesorri-type school. Yet, it was the lesser of two evils at the time.
Ds7, too, had been asking to pull him from school for many months. Three weeks before school ended, he had a complete meltdown. And that was it. Not the way I wanted to end things either. Not good for reducing any anxiety.
This year we've been homeschooling and it's been better. Not always ideal for me or him, but still the best option overall.
Take homeschooling each day or week as it comes, I say. One step at a time. I was very nervous and anxious about it. However, this year ds7 has made such tremendous gains and strides that would have been near impossible in a school (private or public). So success can have many facets to it and not always defined by school or what you may envision learning to be.
Someone once said to me to rip up any mental map of what school was and what I had planned out or envisioned for ds7. This was difficult, but good advice in the end. She meant to say that we're on our own map or trajectory with ds7 and that there isn't a well, defined road to follow here. And this is true.
No one mentions in the parenting books that your child may not be accommodated in a school (public or private). I wish someone would stick that disclaimer or small print in. It would have been nice to be prepared that there is alternative universe to education besides formal schooling that may even succeed how the formal schools operate. And there is. It's called homeschooling or unschooling. Peter Gray's Free to Learn is useful here.