Can/Should I remark my Maths?

Hiya, so today I opened my envelope to receive excellent results, except maths. I got 3 B's, and 4 C's but Maths, I got a D?... It makes no sense to me, due to the fact I was making excellent progress. In March, I sat a practice maths paper (Mock) and was only 5-6 marks away from a Grade C. So, I don't understand how in 2.5 month's I coudn't achieve those extra marks, especially when I was revising effectively.

To add more to the fire, I sat the exam and I breezed through it, I only found 1-3 questions difficult and understood everything and what I needed to do - Defiantly walking out and having Maths as my top in confidence, but instead to just open the envelope and be denied that grade. I really hope, I can get it remarked, I don't think I can pass it in November, especially when receiving this 'D' has affected my attitude so poorly - God forbid what I feel in the classroom...

I pray, that maybe my paper was one of those 'rare occasions' where it's miss-marked by a few marks and then I can achieve my 'C' - to be honest, I ****ing deserve it. I heard that Math's was a hard subject to get remarked due to the fact that its mark scheme is kind of set in stone unlike English/History.

Thoughts?

It depends how far you was off? Honestly don't beat yourself up about it though