For what it's worth, I feel your pain. I've never been a great handgunner even though I try hard. I do well above average on open sights with rifles and have made some amazing shots. Give me a scope or almost any kind of handgun and I turn into Barney Fife. I've gotten a lot better with time and it's taken some honest assessment, frustration, practice, and adjustment to get to solidly average. If you're worst shooting is with your little subcompact, well, that's probably about right. I shot pretty good with a S&W Shield, but did much better with a full size handgun.
All that said, really glad to see someone bother practicing with their carry gun. It drives me nutz when people talk about their range toys but never fire the gun they trust their life with.
"For every problem there is always a solution that is simple, obvious, and wrong." - Mark Twain