How to subtract the value of two cells if vlookup matches on two other cells in Google Sheets

Formula to compare B3 in sheet 1 to column A in sheet 2 (Defined Range Name - COUNTY). If they match then subtract the value of A3 from D2 OR compare C3 in sheet 1 to column A in sheet 2 (Defined Range Name - COUNTY). If they match then add the value of A3 to D2. This is what I have now and it is not adding or subtracting. It just carries down the previous total.

=IFERROR(SUMIFS(OR(VLOOKUP($B3,COUNTY),D2-$A3,OR(VLOOKUP($C3,COUNTY),D2+$A3))),D2)