I would say patriotism is when you love the ideas a nation is built on and stands for, while nationalism is when you love the people and history of a nation.
As a european it's very hard to love the former, since we've been here for more than a thousand years meaning whatever ideas our forefathers might have had in mind are rightfully gone now. However over this time we developed our own culture and became a nation of people which we can love instead.
Nationalism doesn't have to be toxic as it's often depicted, if someone belives their nation is "better" that's called chauvinism. Nationalism is just when you feel your nation is special for you at least and that makes you want to better it.