You've done the right thing, stick with it, do not let him back do not minimise what he has done.
Write it down, here, on paper, wherever you need to so that you don't have to try to get it out verbally when you need to tell people what has happened in previous incidents.
As for the suicide threats... ignore them.
I won't say he won't do it, he might.. if hes going to do it, he's going to do it regardless of what you say or do and it is NOT YOUR JOB to pander to him to try to prevent him doing it.
If he genuinely feels suicidal, it is HIS problem, all anyone needs to do if someone tells them they feel suicidal, is to inform the police/social services and leave them to deal with it.
Using threats of suicide to manipulate a person is another form of controlling coercive behaviour, and whilst it probably means a person does need help it does NOT mean you have to be the one who provides that help, nor does it mean that by allowing them to manipulate you, you are actually helping.
Please don't let this man back into your life, and please do not feel guilty for protecting yourself and your child.