Hi Big Mama,
Your story reminds me so much of growing up helpless against my abusive mother except NO one had the courage to tell her she was abusive and needed therapy to deal with her anger, rage and control issues. (We couldn't use her special fork or eat the ice cream she bought for herself.)
Anyhoo... It okay to tell him you need more time. I learned in therapy that BOUNDARIES ARE HEALTHY. Identifying what feels better means you are on track. Take the time to get strong. He may not realize it but he needs more time too.
Practice communicating with firm statements delivered in a calm manner, without sounding defensive or fearful. A fearful response from you is like a trigger for him... it tells him unconsciously that his methods are working. From now on, if he interrupts you, slightly raise your voice, smile, and again, say, "Excuse me, I need to finish what I'm going to say right now." No need to yell, cuss or get mad.. that feeds the hungry beast!!!
Another thing that helps communicating with difficult people or situations is a sense of humor so remember that on your next family outing. Telling him you don't want a repeat of what happened last time is like erecting a giant hurdle. In family prep... keep it simple and remember an ounce of prevention... make everyone use the bathroom, be as prepared as possible in all things will avoid hassle.
Best of luck from an abuse survivor!