Unable to access Child EA Account settings and parental control

Some years ago i made a child EA account with my mother. After some time not playing I had the problem that i didn't remember the lock in information so i made a new account some days ago which is now a teen account. i found the ID of the old account today and remembered the Password somehow too but i just now realized two things. The child account locks into sims 4 every time i play no matter if i lock in EA with my new account which is annoying since im not able to use some functions. Also the second thing is that i think its some how linked to my steam account which shouldn't be possible coz its a child account which then also makes sense why it locks into Sims 4 since i downloaded it from steam. Every time i try to link the teen Account to my steam account it says that its already linked (attachment). i cant unlkink it since I don't have access to those settings either coz they are online. i also cant access the parental control settings either because my mother and i don't remember the email address of the child account which is the only way next to a phone number to access the setting online. when i try to lock in via the steam connection it always says that an error happend too right after asking if a code should be sent to a guard or parent.

Does anyone know what i can do to at least have access to the parental control settings or is there nothing i can do?