Measure Total

I have a measure "x" that calculates a cumulative of sorts. I want the total to show the value of the last month I am showing in a table, instead of a sum of all (because it is a cumulative). I know this normally works with adding an iterator and the values of all months. However, probably because I am using variables, it is not behaving as expected. When I wrap the measure in another measure "y", it does work to add the iterator. I just rather not add unnecessary measures to my data model. See measures below:

Y = 
MAXX( 
    VALUES ( Dates[MonthYear] ),
    CALCULATE (
        ( x
    )
)
)

X = 

VAR todayMonthYearPlusOne =   VALUE (
                    YEAR ( DATE ( YEAR ( TODAY () ), MONTH ( TODAY () ) + 1, 1 ) )
                        & FORMAT (
                            MONTH ( DATE ( YEAR ( TODAY () ), MONTH (TODAY () ) + 1, 1 ) ),
                            "0#"
                        ))  

VAR tmpBillingPeriod =
    ADDCOLUMNS (FILTER(Deals_Lookup, Deals_Lookup[Won Time (Clone For Reports)] <> BLANK()),
        
        "MonthYearBegin", IF (
            ISBLANK ( [Won Date] ),
            VALUE ( YEAR ( TODAY () ) & FORMAT ( MONTH ( TODAY () ), "0#" ) ),
            VALUE ( YEAR ( [Won Date] ) & FORMAT ( MONTH ( [Won Date] ), "0#" ) )
        ),
        "MonthYearEnd", IF (
                            ISBLANK ( [Lost Date]),
                            VALUE ( YEAR ( TODAY () ) & FORMAT ( MONTH ( TODAY () ), "0#" ) ),
                                    IF (
                                        DAY ( [Lost Date] ) <> -1,
                                        VALUE ( YEAR ( [Lost Date] ) & FORMAT ( MONTH ( [Lost Date] ), "0#" ) ),
                                        VALUE (
                                            YEAR ( DATE ( YEAR ( [Lost Date] ), MONTH ( [Lost Date] ) - 1, 1 ) )
                                                & FORMAT (
                                                    MONTH ( DATE ( YEAR ( [Lost Date] ), MONTH ( [Lost Date] ) - 1, 1 ) ),
                                                    "0#"
                                                )
                                        )
                                    )
                                )
                            )
    VAR tableWithAllMonthYears =  GENERATE (
                tmpBillingPeriod,
                SUMMARIZE ( Dates, [Year], [MonthNum], [MonthYearNum] )
            )
VAR tableWithOnlyWonMonthYears = FILTER (
            tableWithAllMonthYears,
            [MonthYearNum] >= [MonthYearBegin]
                && [MonthYearNum] < [MonthYearEnd]
        )            

VAR tmpTableDeals =
    SELECTCOLUMNS (
        tableWithOnlyWonMonthYears,
        "DealTitle", [Title],
        "Customerid", [Organization ID],
        "monthyear",Dates[MonthYearNum]
   
    )
VAR tmpTableDeals2 =
    SUMMARIZE(tmpTableDeals,[Customerid],[monthyear],"count",1)
RETURN

VAR custcount = 
    SUMX(tmpTableDeals2,[count])

RETURN

VAR X = MAXX( 
    VALUES ( Dates[MonthYear] ),
    CALCULATE (
        ( custcount)
    )
)


RETURN
MAXX( 
    VALUES ( Dates[MonthYearNum] ),
    CALCULATE (
        ( SUMX(tmpTableDeals2,[count]))
    )
)

Sor for example, I have a table as follows: