I cant load into game

After two months of trying, Square Enix Support sent me here to create a thread to get additional support. I cannot sign into my main account. We Changed my internet settings, Uninstalled the entire game, deleted the expansion folders one by one. and still, I remain unable to sign into my main account. One of two things occurs signing in. The game crashes and I have to launch a new instance of it and It stays at a forever loading screen. During this forever loading screen, my friends can still see me online. I tried very hard to wait and even after 5 hours of uninterrupted loading it stays at the loading screen. I can post all the steps we have tried upon request but I really just need help. I was able to create a new account on the same data center and server to log in and play however I cant sign into my account Can someone please help me, as i havent been able to play and am losing not only the cost of my subscription but time with my friends in the new expansion.