Should I do an adiditional option?

I'm currently doing 3 A levels (Psychology, English Lit & Business) and I'm thinking of doing A level Graphics because I have always had interest in Art and Anything Art related but I decided to not do Art for personal reasons (also I had to last minute change my options since some of my gcse grades were not what I expected, so I was made to do English Lit and Business) and there was time to change options but during that week I asked the Careers leader if I was able to do an additional subject (for a different subject which was media) and she said it's better to do something else so I tried not to bother about it however I'm feeling quite confused cause I like the subjects that I'm currently studying right now but I also want to do an Artistic Subject like Graphic Design because I think I would be good at it. I know it is probably late because I asked my form tutor but I'm thinking of emailing and convincing the careers teacher to let me do an additional option. So should I bother doing another A level?

Sorry it's a lot of information at once.