It’s possible you have misophonia. If there’s a noisy eater in the room I have to leave or it really does make the red mist descend. Scraping of bowls also drives me crazy. Some days can be worse than others. Unfortunately there are a few noisy eaters in my life and it’s quite difficult.
Yes, I’ve told them even if it is “my problem”. Slurping and eating with your mouth open isn’t particularly pleasant irregardless of the condition.
https://en.wikipedia.org/wiki/Misophonia
In my case I do feel the irrational feeling that I want to beat someone to a bloody mess, so yeah leaving the room is one of the few options. People in my life who are noisy eaters my wife, my mum, my brother-in-law (now lives in Oz thankfully) and a guy in my office who sits a few feet away who eats apples with his mouth open)