It’s so hard with parents, because they can take it so personally. When I lived at home, I also had to eat at the table with the family, and also could not even look at my dad eating, he was so loud and so vigorous and so oblivious. It really affected our relationship, and was one of many factors that drove us apart over time.
Now, I’m lucky to have an understanding partner. When I first talked to her about this, I explained to her that I have this problem, where things that are perfectly normal and reasonable trigger unreasonable irritation and anger in me. And I explained that she is doing nothing wrong, and I would react the same way to anyone or anything making the noise. I don’t know if my explanation was good, or if she’s just super understanding, but it worked well for us. I basically live with earplugs all the time at home. Sometimes if we’re eating together and I feel triggered, I’ll quietly get up and go put in earplugs in another room and then come back. It makes her feel a bit self-conscious sometimes, but we talk about that too.
Earplugs overall have been a huge help. Instead of seething over neighbours footsteps or TVs, I just cut it all out and wear earplugs. I can still hear well enough to talk or watch TV, but the background noise is gone. I know not everyone is comfortable with earplugs, though.