Here's what I see:
his 'affection less marriage' has led him to begin losing function in daily life and that it's affecting his job performance
He wants me to meet with him so that we can discuss this together.
He wants to meet and convince you to sleep with him and then be able to convince you to do things his way. I may be wrong, but that's my guess.
If all you had was STUFF, it would be different. But you have a child, and he's already voiced the opinion that your special needs kid needs to be put in public school so you can get a job. That to me doesn't really sound like someone who's willing to be reasonable and think of what's best for your son.