These sutuations are heartbreaking. At 25 you can't legally do anything for your son unless he agrees to it and unless he signs a waiver if he DOES agree to get help no doctor or therapist will tell you anything. It's private.
Your son is an adult, even if he is emotionally quite young, and that gives you no control over him. I don't know if his father is helping him or hurting him and I'm surprised your son hasn't left there already. I think he is treating your son horribly and it won't help him. Your x sounds clueless about mental illness, as if he thinks your son is acting this way just to be defiant. You know whether or not the x is being fair.
It is really up to your son to get appropriate help. I hope he will. Many of our adult kids just will not. We can't force it.
What you can do is to go for therapy or join maybe an online/Zoom families anonymous group to learn how to take care of yourself. Overworrying about our grown kids doesn't help them and can be terrible for our health, physically and mentally. We can fix us. We can not fix them.
Sending love and hugs.
