So anxious!!

Tomorrow my mother -in-law is taking me and my girls to a doctors appointment for my ob visit,I can’t drive because of certain medication I take when I’m pregnant, and my husband can’t take us, I’m so nervous though I appreciate my MIL taking us but she always makes me feel bad about myself saying how much weight I gain when I’m pregnant comparing to other women saying I’m weak because I get sick when I’m pregnant, and questioning me as a mother, I’m so nervous to be in the car with her without my husband for a few hours (long hours!) I don’t want to be rude because she’s giving me a ride but it’s hard taking in all she says, she intimidates me a lot but what can I do, anything to ease the anxiety because honestly I don’t know if I will be able to sleep tonight!