17m old is making me crazy

Yall. Our 17m old has flipped a switch. He no longer listens to “no,” he will deliberately do the thing we told him not to do, throwing major tantrums, screaming, etc. I know that toddlerhood can come with a whole new set of difficulties but it feels too soon? I’m also 26 weeks pregnant and feel like I’m in a hormonal rage constantly so things are getting to me more than they normally would but holy moly this child is gonna take me out. Just consistently doing things he has been told not to or going back to it over and over and over. Any advice would be great😭