can’t log in!

Hello all,

I recently switched the theme with which I was working from default to classic. I edited some of the php/css in the template, and I kept getting funny messages when I did it. Now, all of a sudden, every time I try to log in, it gives me messages not unlike the ones that I kept receiving:

Warning: Cannot modify header information – headers already sent by (output started at /home/astridca/public_html/wp-content/themes/classic/functions.php:19) in /home/astridca/public_html/wp-login.php on line 287

Warning: Cannot modify header information – headers already sent by (output started at /home/astridca/public_html/wp-content/themes/classic/functions.php:19) in /home/astridca/public_html/wp-login.php on line 299

Warning: Cannot modify header information – headers already sent by (output started at /home/astridca/public_html/wp-content/themes/classic/functions.php:19) in /home/astridca/public_html/wp-includes/pluggable.php on line 662

Warning: Cannot modify header information – headers already sent by (output started at /home/astridca/public_html/wp-content/themes/classic/functions.php:19) in /home/astridca/public_html/wp-includes/pluggable.php on line 663

Warning: Cannot modify header information – headers already sent by (output started at /home/astridca/public_html/wp-content/themes/classic/functions.php:19) in /home/astridca/public_html/wp-includes/pluggable.php on line 664

Warning: Cannot modify header information – headers already sent by (output started at /home/astridca/public_html/wp-content/themes/classic/functions.php:19) in /home/astridca/public_html/wp-includes/pluggable.php on line 865

I cannot access the blog to make changes. I tried going into my CPanel, into the functions.php file, but I still did not understand what is causing the issue at hand.

Does anybody have an idea as to what the problem might be? Please help!