I've had the same problem, tried everything to fix the problem, username TheLordofCows
You need to reset the password on the linked EA account that account has the persona godsbloodyhelper (not Impeccable_Order your posting on now ) that EA account uses a yahoo email
use the following link to reset the password https://signin.ea.com/p/web2/resetPassword then login on that EA account to fix the swtor account for purchasing
for future purchases, use incognito mode on chrome initially if you purchase on swtor.com to be sure browser cache and cookies is cleared
