Yes, I would accent that it is an experiment for your son but think you do not do yourself justice! Look at how hard you have worked with your son; why do you think his father and siblings would be able to just "walk in" and cure him? You know how difficult your problems are and his, they have not experienced that.

I would think of it as an experiment; you and your son talk together about what he'd like to get with living with his father and half-siblings and what you would like to get, working on your own and having total freedom to work on your own issues, live your own life. No matter whether he goes or not, he won't stay a boy forever, will go out on his own eventually; you should be working with your own life some, taking time for your self and your own happiness; we each have to make our own way, no one else can do that for us.