The only thing I can really suggest is writing an email to the subject leader of the course you want to take. Talk to them directly and explain how passionate you are about the subject and that you can't find anywhere else or that you don't want to go anywhere else. You literally have to make it sound like this is your absolute favourite subject and explain how you would be willing to re-take maths alongside the course. I can imagine this must all be very stressful. Explain the problems you were having and explain how this impacted on your results. Make it evident that you know you can pass it, (sometimes they offer a re-take a few months after you join the college.) Tell the subject leader you'll work the hardest out of everyone and give your 100% effort.