What do I do if I can't remember the answer to my Minecraft account security questions?
Solution 1:
You should try getting support from Mojang itself. It is the only way a problem like this could be fixed because this is the whole purpose of having security questions, as a secondary security for your account. This is the security question section of their FAQ on their website:
https://help.mojang.com/customer/en/portal/articles/797301-account-security-questions