Parse error: syntax error, unexpected end of file

I have accidentally done something to my functions.php file and am now getting the following error message:

Parse error: syntax error, unexpected end of file in /home/newfront/public_html/meritude.com.au/wp-content/themes/HighendWP/functions.php on line 1521

I tried copying and pasting the original content from the functions.php file on my computer from when I downloaded the theme but even that isn’t working.

I don’t know what the heck I have done and now my whole site is down. Please help me fix this. I don’t want to have to start my website all over again.