HELP! My whole computer is FREAKING. OUT.

I have a Mac OS X Version 10.7.5; 2.7 GHz Intel Core i5; 12 GB 1333 MHz DDR3 Whatever all that means.

I've been working on a huge project on Microsoft word, in their publishing layout. It has a lot of pages, which may be part of my problem, but I feel like a computer/program should be able to handle 40ish pages? Anyway, in the past I think I've had problems because of font downloads. Starting yesterday, my Word started crashing when I went to save. It was incredibly frustrating, of course, but I'm desperate to finish this project. This morning, it crashed and it won't reopen!!!! When I attempt to open Word, two of the three pages I previously had open flash up, but when it tries to load the third (big one) the whole things shuts back down. I can't even get it open long enough to close out of that document or try to divide it into smaller documents (assuming that would help at all?). I decided to do system updates, and after that my computer started running even WORSE. Everything was moving slow, the computer is making grinding noises, and I can't get Safari or Mozilla to open! It says it can't connect to the server, but my other devices are on the wifi just fine. (I'm on my MacBook Pro right now… because apparently we're addicted to Apple products). I have tried restarting the computer and it doesn't work. PLEASE HELP!!!