hi, i can understand why you're upset and i'm sorry to hear that you're disappointed. but, please don't take it as a definite for what you'll get. i was in a similar position to you when i was at the end of year 12 and i got an e in biology. biology is really tricky to pick up marks for so it's understandably difficult to get high grades in! in my actual a levels i ended up getting a c because i spent a lot of time doing past papers and focusing on the topics i noticed i wasn't as strong in, and i learned how the mark scheme works. what i'm trying to say is absolutely let yourself feel upset, it's normal and healthy to feel this way, but i promise you that because you got these results now, it doesn't mean that's what you're going to get in the real exams. keep pushing on and i promise you that you'll see yourself improve.