You are wise to recognize the features of an explosive child and ask for help. Obviously, your son's behavior is escalating and now that you're homeschooling him, you realize that something must be done. I could probably come up with some ideas about what might have led to your child's changes in behavior, but you haven't provided me with enough information. At this point, rather than focusing on WHY, focus on WHAT you can do to help your son.
There is an excellent behavioral program that you can use at home to help an explosive child learn how to manage and release his anger. The program will teach you step-by-step how to help your child, so he can overcome his anger and be happy again.