You've been lied to.
Nationalism isn't a bad word.
And no, it's not racist either.
Loving and prioritizing your country/culture does not imply hating or ruling over other countries/cultures no different than loving and prioritizing your family over others is a laudable/healthy position to harbor.
Different interests can, in fact, negotiate mutually beneficial deals/compromises.
Trump often talks about doing so in relation to trade deals where a deal can be had that doesn't intentionally screw us in the process.
That scenario, unfortunately, doesn't work for totalitarian collectivists because regular folks operating on from their own self-interest runs in direct opposition to everything they stand for.
But, the fact is that self-interest is how humans operate naturally - and that doesn't therefore imply to the detriment of others. Collectivists only claim it's a zero-sum game to sell their bullshit to stupid people.
The sad truth is that leftists needs to promote the false narrative about nationalism being a bad thing to help usher in their envisioned new world order.
Don't fall for their crap.
Mike