Hi, it's me answering my own question here because I figured it out in case anyone has the same issue: microsoft changed how this works. so, to my knowledge, you can't make an already existing alias the primary one anymore (don't take my word on this, do your own research I am not affiliated with microsoft and I'm not 100% sure if this is correct)
HOWEVER, if ALL the email addresses in question are NOT mircosoft domain (outlook, hotmail, and maybe more idk look it up) you can just remove the address that isn't primary so it's no longer associated with a mocrosoft account, click the "change" button next to the primary address (reference my screenshot) and add the new address. the old one will be removed from the account (I think you should be able to add it back again, but I haven't tried, so I am not sure)
NOTE: this only works if the email addresses are NOT any microsoft domains (outlook, hotmail and maybe more idk look it up) if they are one of those domains, it will just delete them entirely
I wish microsoft live support chat on no one,
fare thee well