I'm Having Terrible Pain In My Left Side Of My

I'm having terrible pain in my left side of my back and bleaching. Gas indigestion. I tools acetaminophen to receive the side pain.At,6,pm it is now,,7 pm. I drank some water and ate a few ginger cookies.it feels like my stomach is swirwalig around.can I take ,a20 mg famotidine tablet after I took the acetaminophen? How many hours apart?I have acid reflex and gastritis bad. This all started yesterday when I ate out spaghetti that didn't taste good.