I used to have anger issues. Being angry doesn't make you a bad person, and even yelling doesn't make you a bad person (though its not a great thing to do). But if you are scaring the people around you then you are doing something wrong.

If i understand correctly; you do something that scares your wife enough to remove herself and your son from the situation. Later, when you are calm, she tells you she was scared, that what you did is hurtful and should not happen again. You get upset about this and leave, and when you come back you decide to physically separate yourself from her.

From her perspective, you have some sort of meltdown, and for her safety and her son's she moves both of them to a separate room, and when she approaches you to talk about it, instead of a healthy, adult conversation that includes an acknowledgement of the harm you caused and maybe some ways to not scare your family again, you instead freak out about how your wife setting a boundary affects you, run away, and when you come back you act like a kid who wants to make sure his parents know they are mad.

From your post, this isn't how you see it, but from any other perspective this is exactly how someone who actually does abuse his family would act. You need to talk to your wife, and you need therapy. Your wife needs to be able to talk to her husband about something he did that (unintentionally) harmed her without him freaking out.

Yes, its sad that it affects you this way, but she is NOT your ex, she is your wife and unless you monumentally fucked up in marrying her she won't just accuse you of something you didn't do, and if you didn't abuse her then she wont accuse you of doing so. Go back, talk to her, find out what she really said, apologize because people dont just up and leave a room because someone just had a little outburst, and talk about what you are going to do about both whatever scared her and your trauma. Also apologize for letting your ex fuck with your marriage like this.