Calculate cumulative sums and obtain highest value based on it

Hello,

In my large data table with many columns, I have a column for "Month", "Agent" and "Data".

I also have two separate cells located outside the table: H1 (which will have values entered like "2018"), and J1 (which will have values entered like "JAN").

In the table, the month column has values like "2019 JUN" (for all periods from 2012-2020), the "Agent" column has names of people (duplicated for each month), and the "Data" column has a number.

I want to get the highest cumulative sum of "Data" based on the totals of each individual, and which agent achieved that highest total, IF two separate cells (H1 and J1) match part of the content in the corresponding "Month" column.

The agent name "TOTAL" should be completely ignored.

Please see the attachment, as it gives a clearer picture.

Thank you for any help.