Optimizing DAX code (Query exceeding resources error)

For this DAX, I can select individual Items one-by-one and it will populate an actual rate. The issue is a select all situation. If I wish to see all locations Actual Rates, The query exceeds resources, and the visual breaks.

Is there any way I can simplify or optimize this formula? Am I using too many variables?

VAR maxinventorydate = 
    CALCULATE(
        MAX(fct_fsr_inputs[ReportStartDate]),
        REMOVEFILTERS('Date')
    )

VAR beginventorydate = 
    CALCULATE(
        MAX(fct_fsr_inputs[ReportStartDate]),
        FILTER(ALL('Date'), 'Date'[Date] < maxinventorydate)
    )

VAR gallonsdelivered = 
    VAR gallons = 
        CALCULATE(
            SUM(fct_invoice_lines[Gallons]),
            FILTER(ALL('Date'), 'Date'[Date] < maxinventorydate && 'Date'[Date] > beginventorydate)
        )

    VAR stgallons = 
        CALCULATE(
            SUM(fct_st_invoices[Quantity]),
            FILTER(ALL('Date'), 'Date'[Date] < maxinventorydate && 'Date'[Date] > beginventorydate)
        )
        RETURN IF(ISBLANK(gallons),stgallons,gallons)

VAR endinginventory = 

CALCULATE(MAX(fct_fsr_inputs[Tank Inventory]),
FILTER(ALL('Date'), 'Date'[Date] = maxinventorydate)
)
VAR beginninginv = 

CALCULATE(MAX(fct_fsr_inputs[Tank Inventory]),
FILTER(ALL('Date'), 'Date'[Date] = beginventorydate)
)


VAR days = DATEDIFF(beginventorydate,maxinventorydate,DAY)

VAR useage = (beginninginv + gallonsdelivered) - endinginventory

VAR actualrate = useage/days
RETURN 
actualrate/4 ```