I used sugarshacks recipe and a shortening that was regular (not trans-fat free), but it is very soft and verrrrry grainy is there anything I can do to save this big batch? TIA!

What is the brand of your Powdered Sugar? That is usually the culprit of grainy icing. If it was made using "beets" instead of "cane".....you will have grainy icing.

It's Domino Brand

I'm sure some SugarShack icing peeps will hop on here with help. I think it may be in your powdered creamer step.....