Circular Reference Issues - A desperate woman needs help ASAP =(

I have an incredibly in-depth spreadsheet, with about 15 pages, and in-depth tables and calculations on most of those pages. Point being, I have a HUGE freaking file with tons of data collected over the years.

Now, all of a sudden, I cannot input anything without the Microsoft Excel Warning popping up, stating: "There are one or more circular references where a formula refers to its own cell either directly or indirectly. This might cause them to calculate incorrectly. Try removing or changing these references, or moving the formulas to different cells."

I understand what this pop up is saying, but my file is so huge, and there is so much information, I cannot find the error anywhere!!!!! And I don't have the option to search for it. So I cannot correct this error on my own, and I cannot input anything into the spreadsheet without having to exit out of that **bleep** pop up!!!

I am defeated, INCREDIBLY FRUSTRATED, and I cannot see a clear path to recovery. I have been working on this document for years now, and I cannot start fresh. 

HELP, HELP, HELP!!!!!!!!!!!!! SOS!! Anyone! I am desperate and beyond frustrated =(