Please HELP!

Waaaaaahhhhh! I need to put something on my sidebar but I can’t. I can’t find the update button. All I see is “if files were writable then you can edit it”. Oly Guacamole, what’s happening? Please tell me! I did everything from editing the index.php but it did not change. I’m quite frustrated already! I just updated my theme like 3 days ago and it was working fine, now its waaaaahhhhhh! I need your help badly please. Whoever can shed light on this, I’d be very happy and thankful. Please don’t play tricks on me, I’ve been working hard you know, and I don’t have any “brains” left to try and figure out what is wrong!