Hello,
An old computer of mine used to kick me as it couldn't handle the load, I will tell you what worked for me at the time, hopefully it helps. At the login page for the game itself, there is the options tab.. click that, then click 'Video' and i switched that setting to OPENGL instead of DIRECT3D, and it seemed to work for me.
Now, another issue i had was with the login screen via the website. It would continue to log me out.
I found switching programs worked. (For example if using chrome to login via website, switch to windows explorer, and so on. Can't remember which one i was using at the time but i know switching fixed that issue.)
Really hope this helped! ~Sincerely, Birdy