Forgive me if I'm slightly confused, but you're doing C1 in FMaths? If it's the whole of maths in general that's not clicking then I recommend talking to your subject tutors to see if they can help you. It's their job to make sure you understand it. Also, see if you can get another student who understands it to explain - they might do so in a different way that makes more sense. Aside from that, take your time with your homework and make a note of what you did wrong and right, your strengths and weaknesses. Don't be put off by other students doing better because it's not about them.