Issue with sorting a matrix columns

Hi everyone, 
I had a request to have totals of x months on the left side of a matrix table. like in the example below. 

After researching, I found a method that worked with this article. https://4pbi.com/power-bi-matrix-totals-on-the-left/ Which requires creating a calculated table with distinct values of the lifetime in months.
Totalstable = UNION(
    DISTINCT(Sales[lifetimeInMonths]),
    DATATABLE("lifetimeInMonths", STRING, {{"2 months"}}
    ))

and then I have to create the following measures. 

2_months= IF(SELECTEDVALUE('Totalstable '[lifetimeInMonths]) = " 2 months", 1, 0)

SalesWithTotal = IF([2_months], CALCULATE(SUM(Sales[Sales]), 'Totalstable '[lifetimeInMonths] in {1,2}, SUM(Sales[Sales]))
This works, However, since the calculated column lifetimeInMonths is now a text field, I now have a issue with sorting it the right way.
I created a lookup table like this to help with the sort. But for whatever reason, my measure SalesWithTotal then doesn't show my improvised 2_months result anymore

I have officially ran out of ideas. I tried some other things, and I got circular dependency errors.

I'm truly looking forward to your help. 

Best regards.