new private account??

i make a living off promoting brands on tiktok and they often want you to make a custom account for it, so i do exactly what i've done several times. except it made a private account and logged me out of all my other accounts. i managed to get back into all of them except one, and i am so livid that i lost several drafts and have to remake everything. how do i get tiktok to make a new account that's not 1) private against my will and 2) sign me out of everything???