How do I(18f) set boundries with my mother(40f)?

My mom constantly belittles me because of my beliefs and lifestyle. She is very close-minded and doesn’t approve of anyone who is different. I’m kind of the black sheep of the family because I’m the only atheist and more left-leaning person, among other things. I don’t make a big deal out of my beliefs and usually keep them to myself, but my mom always finds a way to judge or criticize me. Recently, my older brother recommended a popular show to her. She ended up enjoying it, and he said he would tell me to watch it as well. My mom responded with, “OP won’t enjoy this.” When he asked why, she said, “She’s too dumb for this.” I'm really upset, because SHE is the one believing aliens build pyramids (literally).

That really hurt. I don’t claim to be the smartest person, but I don’t think it’s fair to call me dumb, especially in front of others. What frustrates me most is that she tends to assume that if something makes sense to her, it must automatically be right, and it’s almost impossible to have a calm discussion with her. I usually try to ignore it because everyone is different, but I’m tired of being belittled in front of other people. I don’t want to change her beliefs, and I’m not trying to argue about religion or politics. She also keeps commenting on my looks and hobbies, saying if she were my age, she would be so much better and all. I’m planning to move out in 2–3 years, but until then, I need advice on how to emotionally distance myself and set boundaries without constantly escalating things.

How can I reduce contact and protect my mental health while still living at home? Thankss!