You really sound like you can handle homeschooling right now and your son sounds like he's pretty miserable. I agree with everyone else. Just pull him out and get him some interesting work to do. He can work and play while you get your work done and you two can go do fun educational outings, etc.
Btw... I'm working part-time from home with a bright toddler who needs lots of attention... I feel bad sometimes that I'm not giving her enough, but I think you can easily pull it off when your child is at such an independent age.
