I'm sorry Kiya that your mother isn't listening to you. Will it be possible for you to buy your own food, which you know you can eat, for Thanksgiving? Since she knows you are allergic to the foods eaten on Thanksgiving, could you stress to her again how important it is that you don't eat any? Most people know allergies can have serious consequences, so maybe you could highlight the dangers and ask her if she would do the same thing to her body if she were in your position. If you feel it wouldn't be possible to have a conversation with her without a massive argument, perhaps you could state it in a letter? That way you get to say exactly what is needed to be said, without interruptions or arguments