Comparing monthly sales over previous year along with year-over-year growth

Hi there,

I have some sales data that is roughly:

Date	Customer	Volume	Product
1/2/2022	A	5	1
1/2/2021	B	3	1

I'd like to get a monthly comparison over the same month last year, then a total year-over-year volume at the end. I tried a pivot table that has the following structure:

Columns: Date, Year, Values
Rows: Product
Values: Volume, Volume2 (calculated field that is % difference from the previous year)

It *mostly* works. I get Something that looks like the following

Product	Jan 2021	Diff from Jan 2020 (which I manually hide because there is no 2020 data)	Jan 2022	Diff from Jan 2021	Total across months, regardless of year	Total differences (?)
1	3		5	66%	8

I feel like I'm 90% there. What I need is to figure out:
1) How the "grand total" at the end is actually a grand total by year, and the diff % is based on those totals
2) Any way to automatically hide or skip the columns for which there is no comparison data?

Thank you in advance!

Edit: added a quick example file