At the stage of nearly deciding 'A' levels... is it finalising?

This is the time that I, and I am sure many others have been waiting for... Finalising their futures.

I suppose I feel positive about the future in some ways, but in others it just seems so far away that I don't have to worry, and I don't have to plan - the reality is I do. I am faced with the reality that choosing these 'A' levels maybe a barrier in my future, if I don't choose right now I'm almost dead-ended in a career. I am pretty certain of a career path I want to follow at the moment, and that is along the lines of maybe Journalism - I love writing, but I am also considering something in Law such as a Barrister? After doing research on both of these career paths they both seem difficult to get into, but I suppose every career path will be complicated and 'difficult', all I need to do is apply myself as I am doing now....