I have spent the last couple of years studying media, film and history in my a-levels and recently i have regretted those choices completely maybe slightly because i'm getting lower than average grades (low b's and c's), and to be honest i only chose media because i joined my sixth form college late. However over the past couple of years I've developed a passion for science and i think i want to study it further as an a-level as my highest GCSE was in physics and that was when science bored me. However i should be leaving 6th form later this year and moving on and i'm really not sure if staying to study science would benefit me.
TL;DR I was just wondering if anyone had any tips for changing a subject or if i'm too late to study new a-levels.
Thanks in advance, any help is much appreciated