Year 12s: what will be the first way you research your future options? >>

Subject help URGENT

Hey guys,
I've been studying maths, Spanish, biology and chemistry for 5 months and I've had to make a very difficult choice. I'm absolutely terrible at maths, I've been getting U's and E's which is unacceptable and these grades have been making me very depressed. In a perfect world I would like to study neuroscience in university and I know you need biology, chemistry, maths or physics so I have to decide wether to continue or drop maths and pick physics AS in year 13. So I was wondering could anyone offer me any advice? TL;DR need to drops maths because I'm achieving badly and take Physics AS in year 13 or continue with maths? Advice needed