Beginner Trouble - Pie Chart Not Putting In Slices Properly

[SirShenLung]

Hello,

I'm a complete beginner at GLS and am trying to make a pie chart for my dashboard that gives a monthly breakdown of my company's Total Overhead expenses. There are 16 categories of expenses we track and I want each of those expense categories to be their own slice in the pie chart which add up to be our total overhead expenses that month. I also want to have a control so I can change the month that is being looked at. 

Here is a rough sketch of what I want:

Here is  a sketch of how the table is laid out in google sheets:

Month:    Rent:   Payroll:  Supplies: ....(all the other categories):   Total Overheads: 

January.   1200.    6000.     500.          .....                                                 83000 (this is just a sum function)

February. 1200.     7000.      750.       ...                                                      Sum of all expenses for February

Continued in this format for every month of the year. 

I've tried reformatting the table so that the months are the column headers and the expense categories are rows but it still hasn't been working for me. The main problem is getting GLS to understand that Total Overheads is a total of all the expenses, not it's own metric. I tried putting Total overheads as a dimension in the pie chart but the pie chart only lets me put one expense category in the pie chart as a metric at a time. 

Thanks in advance!