Clingy 18month old!

She just wants me to hold her 24/7!!!! And crys about everything she never used to be like this but now she literally crys if i wake up in the middle of the night to use the bathroom that I have to take her with me it's too much, I'm 32 weeks pregnant so I can't be holding her alllll the time she will be sitting next to me fine but literally just wants me to hold her or even when we're sleeping she has to be touching me or holds on to my hair 😩😩😩😩 she's been crying all day over nothing and she's also been being mean like hitting me and her brother who's 8 she bit him and made him cry why is she turning into this child of the corn 😐