Cookies are blocked due to unexpected output

Hello all I am unable to login my wordpress site at all, on the login screen it states, “ERROR: Cookies are blocked due to unexpected output. For help, please see this documentation or try the support forums.” I’ve searched and i’ve seen people its either a wp-config.php or functions.php issue. I believe it to be a functions.php issue. Let me give some background from what happen right before.

I was making a small edit in the functions.php file and I messed up the code so I undid my code and everything seemed fine. The next day however I notice the error message and could not log in so I double checked my functions.php file and it all seemed good, tried it again but same error. I replaced it with a backup of my functions file that was unedited but it is still giving me the error message. Please tell me what information I need to give you for support below is a link to my website

http://www.houstonjapanfest.org

Also now strangely if I try to do just houstonjapanfest.org it links to a white page where before it worked fine

Thank you again for your help!