wp-admin Lockout

I need help.

Over the weekend, I went to log into my blog via wp-admin and got a blank page. The main website remained functional.

I tried some of the forums’ advice including shutting off plugins and themes and none of it worked. I had not made any changes to either between the last time I logged in and when I tried to do so again.

After some fiddling, namely replacing the wp-includes folder from wordpress, I started getting the following error message on wp-admin

Warning: Cannot modify header information – headers already sent by (output started at /home/content/50/9153350/html/wp-load.php:1) in /home/content/50/9153350/html/wp-includes/pluggable.php on line 1228

If I understand other forums correctly, that means I have an error in line 1 of wp-load. This is the following code in that line/file.

[ Redacted, don’t post that malware snippet here. ]

But I don’t know what to change now.

Should I just reinstall WordPress? Help!

-Matt