I would love to know if it's my own fault that I'm not good at school

I'm an American going to university in Europe, and it's a lot different than the US. I'm in a study program, and we're as a large group of students in the same major. It's 3 years, and after that, a job and a master's degree is guaranteed. I'm not the best student, I'm mostly in the middle. I'm really worried that I'm going to fail or get kicked out, because of the pressure I'm under. I don't know if I'm exaggerating or not. I know I can do it, and I do okay. But I know I'm not good at school, I'm only 75% sometimes. <br><br>I think I could be lying to myself.