Add new columns to Pivot table

[tomf122]

I am trying to create a pivot table such as below where i am able to show both the current month total and the previous month total as stand alone columns in the pivot table. The total would be the value of all the months added together on right hand side of the pivot. Currently i have the pivot set up dynamically so the user can switch between different years and months and the values will appear. Is it possible to add these two columns to a pivot table.   I am working with a date field and a value field. 

Goal: 

Current Attempt.