Deactivated my account by mistake

Hello, I am currently using my sister’s account.
I deactivated my account by mistake, because I created that account with student email address. I only have 1 phone number. Now that I have finished my studies, that email address will be deactivated anytime soon. So, I deactivated it. I am trying to make a new account with my phone number, it would not let me. So now, I am trying to reactivate my account as I have no other choice. Are there any ways to unbind my phone number?