The truth is, to be sure of gaining admission, you have to apply with at least c6 in maths. Right now it will be very good if you can rewrite the maths even though i know it will be difficult for you because you don't like maths. If you decide to rewrite it, that would be the best option. Also i know people in UEW who had d7 and did not get there by protocol. So what we should do is;
Next year, rewrite and at the same time apply with your current grade. if the admission list comes and you get admission then you can either go ahead and write the maths for fun or not write at all since the admission list will come before you write the novedec. On the other hand if the admission list come and they did not take you, you will just go ahead and write the maths and reapply the next year. This is the best option.