How do I fix my return if I thought no one claimed me as a dependent, but my mom did?

I didn't know until my tax return got rejected that my mom listed me as a dependent on her tax return for 2018. How do I amend these issues? When I try to click back through and fix it in TurboTax's automated system it doesn't show me where the errors are. Also, will I have to amend my W2 first? Thank you!