There are all kinds of tricky situations – we completely understand! Family gatherings, social, business lunches, etc. There are cultural differences to consider, in some cases, also.
For big parties, the office holiday party, church pot luck dinners, and similar – these are often the easiest to deal with. As has been said before, most people don’t even notice! In the early days, do yourself a favor and eat BEFORE a meal. It will be so much easier on you if the choices are limited.
Bring one dish you can eat. Cheese platters, (with pepperoni, sausage, and crackers, if necessary), deviled eggs, shrimp, meatballs, crust-less quiche, sliced deli meat platters, a roast beef, there are really a lot of party foods you can bring, if appropriate.