Help creating a 'delta' chart

Hello, I am new to Power BI and would like help creating a 'delta' chart based on the Bough / Sold amount for a sample Sales table. I have the following table below:

Based on the table above, I create 2 charts which is 1) Bought Amount Totals per Month and 2) Sold Amount Totals per Month.

Bought Total per Month which sums up the "Buy" column if "Sold = 'NO'" and "BoughtMonth = Month Criteria"

Sales Total per Month which sums up the "Sold" column if "Sold = 'YES'" and "Sold Month = Month Criteria"

I have already created the following above in Power BI. My data source is a SharePoint List, which is based on the Sales Table. Now, I would like to create a "Delta Table" showing the difference between the Sales and Bought Totals per month, something like this (which I created in Excel):

In Excel, I have done this easily because I was able to create manually table and just calculated the deducted values like so:

But in Power BI, I am having difficulty creating the table above. Please note that for reasons, the Sales Table cannot be re-structured anymore. I can add calculated columns and such but I can't remove any of the existing columns there.

Please help how I can do the delta table