I remember I also had a problem with logging into the game, it turned out that when I ran the launcher, then there are two options, an error screen appeared, or it started with artifacts on the screen. I managed to fix this error by downloading the same version of the launcher, but through
thepiratebay, through which I started the game. With logging into my account I had no problems, so it is likely that you either gave the wrong username or password, or you were blocked. This can be fixed by restoring your password or login in via Email.