Learn to laugh at yourself, and some of the predicaments you get yourself into. You can go through life with a sour and serious view of just about everything, or you can take a step back and realize that there is a little humor in most awkward situations. Loosen up, and laugh a little. It will likely add as many years to your life, as your vegetarian diet. Although it may not be easy, try to forgive and forget.
People often speak before thinking, and hurt others, sometimes without even realizing it.
Holding a grudge will not make you feel better, only more stressed. Realize that you can't always make perfect choices. Think about your goals in life, and set some priorities. For many, the number one priority is the people we love. As a vegetarian, you have likely made a lifestyle choice that is very different than the rest of your family.