Calculate totals within custom SQL query (Tableau)

I have a dataset where I wish to reflect the totals from a custom SQL query I performed in Tableau. Here is some sample data:

1. I first performed a custom query that was a join, unpivot and placed my data into groups

Size Tb   Val       type           Group      Sum_AVG    SKU       Last_Refreshed

270      90.5      Free_Space_TB  Group2     90.5       Excel     9/1/2020
270      179.5     Used           Group2     179.5      Excel     9/1/2020
814      701       Free_Space_TB  Group1     701        Gris      8/1/2020
814      112       Used           Group1     112        Gris      8/1/2020
   

2. Then I aggregated the data by taking the sum of one group and the average of the other group (and final summed these groups values)

The data is being aggregated like this: (SUM_AVG)

zn(sum(if [Group]= 'Group1' then [Val] end))
+
zn(avg(if [Group] = 'Group2' then [Val] end))

The view looks like this

Here is the custom query output

Here is my view

The avail and used appear when I hover over, but how would I include the total?

This is the calculation I am using (thanks to help from a SO member):

{SUM({Fixed [type]: ZN(sum(if [Group]= 'Group1' then [Val] end))})
+
sum({Fixed [type]: zn(avg(if [Group] = 'Group2' then [Val] end))})}

I am doing something wrong, because it is totaling up across all the column(s), (I have more columns in the full dataset) when I just want the total for each column.

(Used was created from using a custom query)

Any assistance is appreciated.