HLOOKUP with moving row_index_num

I have this data setup in this way because its how its been produced from the inventory database:Screen Shot 2020-05-02 at 9.09.05 AM.png

Im using HLOOKUP on column BZ5 for example:

=HLOOKUP(BZ$1,season,2,FALSE)*($BK5+$BL5*BZ$2)

where BZ$1 is the lookup value, month name "January"
where season is currently the SI range from BN4:BY5 because I was working on that first row, row 5.
where 2 picks the 2nd row in my range, which would be row 5 value for SI in order to multiply it by the LTF.

But for the second product, row 6, the formula is copied properly except for the season range:

=HLOOKUP(BZ$1,season,2,FALSE)*($BK6+$BL6*BZ$2)

Do I set up my range differently or how do I make the range's 2nd column move? Or do I need to select the entire range down to my last row, but then how would I select the row_index_num?

There are instructions at the top of the page explaining how to attach your sample workbook.

Please try at BZ5

=HLOOKUP(BZ$1,BN$4:BY5,ROWS(BN$4:BY5),0)*($BK5+$BL5*BZ$2)