Hello Esteban Martinez3 ,
Thank you for posting in Microsoft Community forum.
Due to your current old email account being unusable, we suggest that you contact the VLSC Support Center to link your new account with your old account through other means.
You can find the contact information for your region's VLSC Support Center by filtering for your region and location.See also Support Center Contact Info. | Microsoft Learn
I hope the information above is helpful.
If you have any question or concern, please feel free to let us know.
Best Regards,
Haijian Shan