the base idea of nationalism is to protect your people/culture, borders, etc. and maybe occasionally help out others when we can (like for example if a major natural disaster happens or something along those lines) and try not to cause more problems during hard times
you can be a nationalist and still hold a respect for other cultures while wishing to uphold the preservation of your own
you just described nationalism on paper. Unfortunately, what you described rarely exists in real life. An example of wanting what's best for your country is if there was a disease ravaging the population and you were to insist that we help ourselves before others. However, we live in a time where the country is not experiencing any major problems. Any problems that do exist, i.e. Flint michigan's water crCIA, detroit's education crCIA, etc. are not being addressed currently, while problems that involve foreign events, such as syrian refugees, immigration, and israel are being blown completely out of proportion by news, media, and even the president.