Switch returns wrong totals despite SUMX

Hi Community, 

I am new to Power BI. I am trying to build a Balance Sheet from an financial statement which has a few line items recalculated.

I want the code to sum up the Balance sheet using for the positions that are recalculated the corresponding values and for the others the values that were input for the model. 

I researched already here and thought, that SUMX would to the job. However, I can't get the totals work correctly. 

My Measure is the following (Where [Total Amount] is the input numbers and DIM_Structure[Account] is the line item structure of the Balance Sheet: 

Development_Ergebnisübertrag =

var selectedlevel = SELECTEDVALUE(DIM_Structure[Account])

var PnL =

    CALCULATE (

                TOTALYTD([TotalAmount],DIM_Date[FullDateAlternateKey]),

                ALL ( 'DIM_Structure' ),

                'DIM_Structure'[Statement] = "GuV"

    )

 

return

SUMX(VALUES ('DIM_Structure'[Account]),

switch(

        TRUE(),

        selectedlevel = "Ergebnis der Periode", PnL,

        and (selectedlevel = "Gewinnrücklage", MAX(DIM_Date[Monatsname]) = "Dezember"), 10,

        [TotalAmount]

)

)


The result is brings back wrong totals:
 

 

I thankful for eyery tip how to solve this. 

Best regards