It says, "Invalid Username/Password"?

[ReneeGoMusic]

Hello,
I am a newby(new-nooby) here and I just created an account on this website about an hour ago. I've already activated it and I already downloaded the game. When I tried to go on multiplayer, I entered my username and password, correctly, I did it for like 5 times but it kept saying,"Invalid Username/Password". That's when I decided to go to the forums; I saw a post about it, and someone said to create an account IN-GAME so I did that (Using my account user and pass from this website), but it says,"Username in use", or something like that.

How I fix this? I really want to play this game. 

[FaintSilhouette]

You can't fix it. You'll just have to pick a new username on a new in-game account. Or add some numbers to it. Hence I used to be "Silhouette" on many sites until I ran into a few where that was taken, so I took up the name "FaintSilhouette" to reduce the likelyhood someone would have the same name.

[Myz]

"WatermelonDrops" already exists and was made a long time ago. So yeah, pick another name for you ingame account.

[ReneeGoMusic]

Ohhhhhhh. It makes sense now. I read the rules and guidelines thingy when I was downloading the game and it said not to have multiples account. So I tried to avoid that.
I just made my in-game account.
 Thank you though!