With all due respect to Orwell, I define nationalism as nation's self-governance.
Yes, it's sort of desire to take power from bigger multinational structures back to the nation. But at the same time it's defensive from nation's perspective.
If you define nationalism as something other than the commonly accepted definition, then complaining about how people use it seems like an exercise in frustration.
This is the historical definition. And still one of two definitions common definitions. The other one trying to conflate nazism and nationalism. Which is just Orwellian doublespeak.
Orwell seems to describe what you’re defending as patriotism, not nationalism.