You need to tell him that your family therapist and your doctors are telling you different...
He is MIND READING. He is also not a qualified FT or psychologist so where is he getting this stuff?
I know you don't want to get into an argument but he really shouldn't be steamrolling his entire family into divorce without their commitment to it or their consent.
I am wondering if you can get your doctor to explain to him that pressuring you and your kids through a divorce right now is NOT healthy for your recovery.
He needs to hear that... and if he can back off, then you have time to educate him about the damage divorce does to kids and adults both.
He needs time to educate himself... but he wants to learn the hard way right now, someone needs to tell him to SLOW DOWN and that racing at high speed to divorce is not healthy.