Frustrated with inability to do body work!

I would skim coat that with metal glaze and work it with 180g. one last time. I don't pile on primer like it's body filler. Priming over 80g scratch can lead to sand scratch swelling later down the road after the paint is on. Some primers whether epoxy or 2k require an etch primer underneath so you have to look at the tech sheets for the brand of primer you select to find out what's required.