Welcome! I'm glad you found us.
Sorry about all the questions, but your answers will help us point you in the right direction for help.
What kind of doctor diagnosed him and what kind of doctor is treating him? Was his last evaluation at age 9?
Has he seemed better or worse or about the same since you pulled him off his medications? When exactly did you take him off the medications?
Does he have an IEP at school?
In terms of the school, you might want to post on the Special Education 101 about what the school is telling you. If this is a public school, the school cannot simply tell you to homeschool your son. If the current placement is not working, the school must find a suitable placement to allow your son his right to a free and appropriate public education (FAPE).
You might want to pick up a copy of The Explosive Child by Ross Greene. It has helped many of us on this board parent our extra-challenging children.
Again, welcome. You will find a lot of support here.