Login Error – Internal Server Error

Hello,
I installed my blog a couple/few weeks ago and was able to login and make changes, including changing my theme, etc… Since then I have tried to login on 3 different computers and it won’t work. I can go to my blog, but when I attempt to click the “login” button I get this error:

Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, webmaster@silverdoves.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

Does this mean that the problem is with my domain or something? I didn’t make any changes when I last was able to login, at least to my knowledge. Any help is appreciated. I have tried to re-upload some of the files (but not all since that would take awhile and I don’t know which files are relevant to this issue)
Thanks to anyone who can help me out.

Brittany