I’d file a written complaint. Email. So there’s a record of it. Describe what happened. Then follow up to find out if course of action was taken. He should never be allowed to speak like that

I’d not judge your friends for not wanting to argue in a restaurant. it’s not comfortable to start arguing. Maybe they should’ve but it’s not easy. You are in a bad marriage yet you don’t speak up and don’t leave and don’t stand up for yourself. You described some other bad situations with people and again you’d not speak up and don’t stand up for yourself

Your friends weren’t comfortable to argue with a waiter. Not everyone can stand up for themselves. You don’t.