Based on the information you've given and difference in behaviour pre and post the trauma I'm inclined to think this is a mental health issue as opposed to anything else.
In this situation i can understand your actions OP and do not agree that your first priority ought to be to walk or "kick the fucker out".
That said as pp's have already communicated you can't take responsibility or ownership of his mental health.
I appreciate why you've "tiptoed" around the elephant in the room, but if he is suffering from PTSD or other MH issues, your attempts to fend off another episode by shouldering all the burden of parenting, doing anything to keep him happy etc will do little other than delay the next emotional "explosion" as you put it.
Your contribution to the situation is at present (albeit unintentionally) maintaining an unhealthy and unsustainable dynamic.
My advice is that you need to speak calmly frankly to your husband and "show" him the elephant.
This is no way for any of you to live and sooner rather than later your children are going to sense (or see) this awful tension and anxiety that pervades your home (if they haven't already - and even very small children are far more perceptive than many people realise).
You can't get help for him - he needs to do that for himself, but you can support him in doing so.
Offer to see the GP with him. Talk about counselling services. Tell him there's no shame in a response to trauma that impacts MH, the shame is in abdicating any responsibility in seeking treatment at the expense of your loved ones and that's something he can fix.
Explain that your scared and worried.
Be blunt that something has to change because as a family you can't go on like this and say that the next time he leaves you'll let him go and call 999 if that's what it takes to get some level of medical intervention unless he'll do it himself.
Also steel yourself to acknowledge that if he won't seek help you may have to leave to protect your own mental health and welfare of your children.