As numerous physically abused women have discovered, it's highly unusual for a violent man to be given a prison sentence for a first offence unless he's caused serious bodily harm or worse but, regardless of gender, being subjected to violent attack is, to use fluffiphlox's phrase, 'one hell of a shock' for the victiim.
It would no doubt seem to many who have been on the receiving end of violence that being required to spend a few weeks as a full board, with frequent use of phone, guest of Her Majesty is not a punishment that fits the crime.
However, be that as it may, the forgotten victims of crime are the offender's close family members who may be, or feel, stigmatised by his/her criminal acts and where an offender has dc, it's often the case that they are disproportionately adversely affected by the imprisonment of their dp(s).
That said, it seems to me, OP, that you have 2 dc by an ex-knob and 1 dc by another knob and, in saying when its good its ace but then when its bad its heartbreaking, I am wondering what time periods you are referring to?
Is now a 'bad' and 'heartbreaking' time because of your enforced separation, or is it 'good' because you know where he is and that where he is gives him little opportunity to cause the police to knock on your door, or for him to cause you heartbreak by other means?
In any event, given that you are bearing the brunt of the consequences of his antisocial behaviour it is, as Cogito has observed, cruel of him to treat you in this manner and it would be cause for considerable concern if he is doing so to relieve any feelings of powerlessness over you he may be experiencing due to his freedom being briefly curtailed.
If this is the case, he is unlikely to be man who has learned much from this experience and it is to be hoped that his continued exposure to daytime tv can be relied upon to effect his rehabilitation before his release.
With regard to your title question, should you decide to terminate this relationship whether you go depends entirely on whether the property you live in is in his name alone and if it is not, in order not to further jeopardise the stability of your dc, he should be the one to go or not be re-admitted to your home, as the case may be.