Sort Table by Month using work around without losing sub totals

So I want to sort my table by month, and in the correct calendar order. Since it's not possible I use a work around and create another field with numbers, put that in first column & sort low to high, and hide the value under a display rule. I then also sort by month in the second column. This works great....unless you want subtotals for each month. When you sort by two columns you lose the sub totals.

I don't like the pivot table reports, they are fussy, and I also want to be able to in-line edit.

Has anyone solved this problem? Any ideas?