A Level Maths or A Level Psychology?

So I am going into Year 12 and have decided to do A Levels Biology and Chemistry. I want to go into a science/medical related field, however I feel like A level Maths would be too difficult as I've already attempted some of the work our school sent but ended up struggling a lot even after help from various resources. I am opting to do Psychology, but I am worried that this would hinder my chances of being able to do a medical/science related degree. I know that I can get a better grade in Psychology over Maths as I've already started making notes on Psychology (finidhhsed topic 1) and it wasn't too bad overall. I know that all subjects will be hard in some way but I want to know whether I'd be at a disadvantage and, if I am, what I could do to make up for me not taking A Level maths (sorry for waffling).