I would just like to say that you most likely have the ability to get through the course, if you were not up to standard you would not have been accepted onto your course by the university. Saying that, Mathematics at university is hard, but I completely disagree that only the naturally talented ones succeed. Working hard is far more important, and if you are struggling it is probably through lack of effort or not studying effectively rather than you not being smart enough or whatever.
It is still early enough for you to work a bit harder and get into a good studying routine, get help from your personal tutor if you need to. It is important to not fall too far behind, and a lot of people don't like the idea of working hard but that's really the only way.