.php issues: dashboard and blog itself come up blank

Hi there,

I’m having major issues, I think with .php in my TwentyTwelve theme. I can access https://wordpress.com/my-blogs/, but anything I click that has .php at the end comes up blank, including my Dashboard and blog itself.

I made a change in my functions.php file because I had issues with my RSS feed and then everything went blank, so I tried to reload my functions.php file from Updraft Backup (from 25 Nov) in PHPMyAdmin through my host service (with SQL compatability mode NONE), but it comes up with an error message:
ERROR: Unknown Punctuation String @ 1.

And then at the bottom: My SQL said:
#1064 – You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘<?php

if ( ! isset( $content_width ) )
$content_width = 625′ at line 1

I’m in way over my head here. Can anyone please help me? My blog is currently blank (wordpress.elizabethbarlo.com) and I really don’t want it to be!

Thanks so much in advance.