I accidentally file taxes when i am under my mom and I dont know what to do. She cant get her stimulus check because of me. What do I do?

How old are you?  If you are over 16 she would not get stimulus money for you.  Do you mean she cannot e-file her 2019 return because you did not mark that you could be claimed as her dependent?

I SHOULD HAVE SAID I COULD BE CLAIMED AS A DEPENDENT

Did you say you could not be claimed as someone else’s dependent, but it turns out your parent(s) can claim you?  Now your parents’ return is being rejected when they e-file, or it will be rejected.  That means your parents must print, sign, and mail their return.  They can still claim you as a dependent, but they cannot e-file now.  Not even if they wait for you to amend, so they should not wait for you to do that.

Your part in fixing this is to wait until your return has been fully processed and you have received you refund.  THEN you need to file an amended return, called a 1040X, to change the way you answered that question in Personal Info about whether you can be claimed as someone else’s dependent.  You will have to print and mail the 1040X—it cannot be e-filed.

How do I amend my 2019 TurboTax Online return?

If she has not yet filed a 2019 return they will use her 2018 return for the stimulus check.

https://www.irs.gov/coronavirus/economic-impact-payment-information-center