Feeling worthless

I am the oldest and only girl child in my family. My step mom is pregnant because she his being a serrate for her brother. We were on a little vacation and heading home but all during the trip my step mom kept calling me a dumbass, bitch, stupid, or saying blonde jokes. I know I'm not smart but it hurts when I'm told over and over again. My step brother joined in too and that hurts because I'm always there for him. And my dad kept redoing everything I did even tho I did it correctly. It makes me feel like I can't do anything. I try to help and I know I forgot things and I don't mean to. She said that doesn't really think I'm stupid but honestly I don't believe her. I feel so bad and I hate myself but I don't share my emotions with anyone and I bottle them up till I just sit outside and cry. I feel so empty. I just want to help but ican't do anything right or without pissing my mom off. I love my family soo much. We are just going through a rough patch and it will get better, I hope. Im Sorry if this sounds like I'm complaining. I just needed to get this off my chest, sorry again.