Sumif + Index + Match Trouble

Hello,

Here is my situation:
(See Picture)

The three left columns are constantly being added to. The Category 1 and Subcategory 1 columns never change, they are the table of constants. Total Amount- the last column, on the right- needs to show the sum of the amounts that are equal to the Category 1 and Subcategory 1. I currently have the formula: =INDEX($C$19:$C$27,MATCH(D19&E19,$A$19:$A$27&$B$19:$B$27,0)) which gathers the value of the amount, but only takes the first value, not the sum of the values. For instance Financing Partner should be 600 total.

How do I add Sumif to my current formula to make this happen?