For me I find chewing on gum or a toothpick etc is very beneficial it calms the acidity and helps prevent hyperventilating

I find that going on YouTube and listening to binaural music for nausea to be helpful for both aspects, especially if you can find a quiet area! I also drink tea that has any ingredients such as ginger, lavender, peppermint, chamomile, anything related to relaxation for digestion + anxiety because the anxiety can heighten can nausea so combating them both with combining those herbal teas has been something I use as well