M.K.
I would also try to call the police (non-emergency) and social services as soon as possible. If you feel you child is in danger when he is with his father, keep talking to authorities until someone listens. Don't give up if one social worker doesn't respond. Also, if he was in Iraq, he may have very serious mental health issues that could negatively affect your children, especially because you mentioned him "shaking" your child. Please find a lawyer as soon as you can and they can advise you. Best to you!