Oh, GS honey...
how painful. It's true that a lifetime of these experiences make us so much more sensitive to that kind of behavior and bring up the whole weight of the past, threatening to overwhelm. In the face of that - you were the voice of calm and reason. Poise, grace under pressure... yes, you have reason to feel proud of yourself.
BUT: you mentioned that the restaurant staff and several other people attempted to intervene and assist you to quiet the raging madman.
THERE is your solace and comfort - in the fact that others at the scene were able to clearly see who was in the wrong, and in the fact that they were willing and actually DID try to help. I'll bet the witnesses to the rage, were rooting for you... sympathized with you... and I know they didn't blame you for the ruckus. How could they, with King Lear holding forth and trying to attract all the attention to himself? He made himself look like a fool - it wasn't anything you did or didn't do, that called that forth.
Please don't "own" the responsibility for this man's behavior and feel any shame on his behalf. He's not your fault. It's not your job to control him or his behavior. You didn't make him this way... and look how far you've come: from your description you were far from paralyzed. You took reasonable, calm, intelligent and caring purposeful action. You were the "resident adult" in the situation.
And I think it was your grace under pressure & bravery that called - attracted - help to you. That's what I call "there"!
Your father doesn't know it - but he gave you a perfect opportunity to prove you're there. Don't slip into the old patterns of seeing just the hurtful part of the experience - look for and commend yourself on how free you were from the old paralysis. Remind yourself always when thinking about this incident how your bravery in facing him brought you HELP, others to your cause; who CARED, people who were championing your wish to quiet him - how you did exactly the right thing - and realize that you no longer have to protect yourself from him:
he only humiliates himself. The humiliation only sticks to him. Not you.