Okay, all I am saying is don't do Maths or Chemistry unless you really really enjoy them and believe they will be beneficial for your future. I do maths at A-Level and believe me I find it tremendously difficult and I got an A at GCSE, also most of my friends have done Chemistry and well let's just say it's not looking great for them at the moment.
Do what you enjoy! It sounds like you like Media so do it! Even if you think the industry is impossible to get into, it doesn't mean you have to take that career path just because you have done an A-Level in it. At the end of the day it's more about the grades if you want to get into a Uni and mainly less about the actual subject in most cases, that being said if you love Media with a passion why not push yourself and go for a spot in the industry, I really believe that nothing is impossible if you really want it.
I am doing, Economics, Maths, Geography and History at A-Level, Maths I enjoy but is very difficult, History is great because I have awesome teachers, Geography is something I am interested in and Economics I hadn't done prior to A-Levels and find myself struggling in it immensely so will be dropping it, it was not what I thought it would be.
Good luck on choosing and go with your gut instinct, don't think about it too much and pick what you enjoy because that will guarantee you the best grades over something that you hate!