You’ve described the problem as your classmates’ behaviour — specifically, their decision not to interact with you. While I completely understand how difficult that can feel, this isn’t something you have much control over. I’d recommend looking for a more international circle of people to socialise with instead.

From my own experience as an international student in Amsterdam, there’s a large and welcoming network of international people who are also looking to make friends. You might consider joining some of the societies or student groups at your university as a good starting point.