Suspended from other job

J • 27 and working on my second child. Full time medical assistant and going back to school for my RN.
I am a medical assistant during the week and I waitress on the weekend. We have this ass of a manager that when he gets mad he takes it out on anyone and starts an argument. So yesterday when I am almos done serving tables I was waiting to run food and the one I was going to take wasn't ready. I told the expo I will be right back to check on my last table and came right back a he started raising his voice saying why didn't I take a tray and I said it's wasn't ready and everyone else took the others. He then kept following me around barking orders and threatening to fire me. Now I did admit that I was wrong for talking about the situation to others because they kept asking what was wrong. Then I told him he couldn't fire me because we need to run the situation through our GM. So he replied o I can't do anything? And later wrote me up and suspended me for a week saying he coached me through the situation and I was doing nothing for several minutes. And took time away from my team member tables when they where coming to me. I wrote a front and back letter on the remarks and he got upset about that. I told him he was petty and was doing it only to prove a point which he swore he wasnt. Smh... my coworkers told me to call HR and report it.