VPN is on when you try log in game ?
If so turn it off.
If not this is your internet problem, most of chance this is your problem.
If you have addon installed, delete all of them, let blizzard install the addons one more time.
make sure all your version wow and wow-64 are up to date, check again the database and WTF file to make sure everything is in order.
Let us know.
Nino