Need to combine 20 IF statements

Data Priority Grid test calculations.xlsHi everyone, this is my first time on the forum and I really need some help.
I have a scenario where I need to combine 20 if statements into one formula. I currently have 4 separate nested IF statements with 5 IF statements in each.

I'm trying to create one formula that defines a priority grid (i.e. whether an item is priority 1,2,3 etc) The criteria I need to evaluate is the Value, whether the status is TRUE or FALSE (this relates to a registration status) and also the number of months - calculated from Today.

I've attached the excel file which shows the criteria grid as well as the first 4 calculations I've managed to create.

Essentially I need to combine the follow 5 statements into one formula:

=IF(AND(A3>=2000000,B3="TRUE"),"1",IF(AND(A3>=2000000,B3="FALSE",DATEDIF(TODAY(),C3,"m")<6),"1",IF(AND(A3>=2000000,B3="FALSE",DATEDIF(TODAY(),C3,"m")>6,DATEDIF(TODAY(),C3,"m")<12),"2",IF(AND(A3>=2000000, B3="FALSE", DATEDIF(TODAY(), C3, "m")>12, DATEDIF(TODAY(),C3,"m")<24),"3",IF(AND(A3>=2000000, B3="FALSE", DATEDIF(TODAY(), C3, "m")>=24),"4")))))

=IF(AND(A3>=1000000, A3<2000000, B3="TRUE"),"2",IF(AND(A3>=1000000, A3<2000000,B3="FALSE", DATEDIF(TODAY(), C3, "m")<6),"2",IF(AND(A3>=1000000, A3<2000000, B3="FALSE", DATEDIF(TODAY(), C3, "m")>6, DATEDIF(TODAY(), C3,"m")<12),"3",IF(AND(A3>=1000000, A3<2000000,B3="FALSE", DATEDIF(TODAY(), C3, "m")>12, DATEDIF(TODAY(),C3,"m")<24),"4",IF(AND(A3>=1000000, A3<2000000, B3="FALSE", DATEDIF(TODAY(), C3, "m")>=24),"5")))))

=IF(AND(A3>=500000, A3<1000000, B3="TRUE"),"3",IF(AND(A3>=500000, A3<1000000,B3="FALSE", DATEDIF(TODAY(), C3, "m")<6),"3",IF(AND(A3>=500000, A3<1000000, B3="FALSE", DATEDIF(TODAY(), C3, "m")>6, DATEDIF(TODAY(), C3,"m")<12),"4",IF(AND(A3>=500000, A3<1000000,B3="FALSE", DATEDIF(TODAY(), C3, "m")>12, DATEDIF(TODAY(),C3,"m")<24),"5",IF(AND(A3>=500000, A3<1000000, B3="FALSE", DATEDIF(TODAY(), C3, "m")>=24),"6")))))

=IF(AND(A3>=200000, A3<500000, B3="TRUE"),"4",IF(AND(A3>=200000, A3<500000,B3="FALSE", DATEDIF(TODAY(), C3, "m")<6),"4",IF(AND(A3>=200000, A3<500000, B3="FALSE", DATEDIF(TODAY(), C3, "m")>6, DATEDIF(TODAY(), C3,"m")<12),"5",IF(AND(A3>=200000, A3<500000,B3="FALSE", DATEDIF(TODAY(), C3, "m")>12, DATEDIF(TODAY(),C3,"m")<24),"6",IF(AND(A3>=200000, A3<500000, B3="FALSE", DATEDIF(TODAY(), C3, "m")>=24),"7")))))

Any help would be greatly appreciated as I'm now completely stuck :-)