It's really hard to know, from what you have said, whether he has a problematic temper or whether you are experiencing it like that because you don't like him. None of us are there or have witnessed the arguments..... Your suitcase comment would have been a bit of lighthearted banter between some couples, and a hurtful criticism among others - totally depends on context, how it is said etc.
But to an extent I think his temper/the PTSD is a red herring here (and forgive me, I don't mean to be dismissive - if he is aggressive and scary that is obviously not acceptable and I am sorry that happens to you).
But the very clear thing from your post is that you don't love the man any more. In fact, for whatever reason, rightly or wrongly (if there even is a right or wrong here) you are embarrassed by him.
But, it makes financial sense for you to stay.
And the brutal truth is, many many people stay in relationships for that reason. I have a friend who fell out of love with her (perfectly nice, but no doubt a bit infuriating) husband 10 years ago now, but stays because she loves her house and couldn't afford it on her own, plus her daughter is happy and close to both parents and she fears upsetting her.
If it were me I would leave. I have done so a few times, to my greater impoverishment, because I can't live a lie and pretend to be in love with a man when I am not.
But plenty do, so I won't judge you. Indeed, perhaps it's even the right thing to do to put your kid first? I don't know.....
The questions I would ask myself, and answer as honestly as I could, if I were you, would be:
A) if I stay, will I be able to control my words and refrain from saying, unprompted, things that are hurtful, rude or dismissive of him.
B) what will sex be like. Can I still have enjoy sex with him? (Please don't force yourself if you dislike it). If I can't, is he the sort of man who can thrive in a sexless relationship?
C) will I be tempted to cheat? If so, what will that do to him?
I hope you come to a decision that works well for you all.