Sick Gramma?

I had my lights off in my tank tonight, and i heard my shrimp hit the cover. I turned on the lights, my gramma is on the ground on his side, my ocellaris seemed shocked, (i could touch him without him moving) and the shrimp was all over the tabk. Everyone else seemed fine. I recently introduced an artificial anemone to the tank and noticed when i was isolating the shrimp some of the coloring had flaked off! I pulled my crab and shrimp, and the 2 artifical plants. Nitrites are 0 and ph is 8.2. Gramma is on his side taking slow big breaths. He was sort of twitching for a bit and then went into my liverock. I havent seen his since and i am very worried. He never hides and is super interactive. I dont want to loose him.