Keep it! It is a rewarding and good subject to do! Trust me in my prelims I was ranked just inside the top 10 and in the trials I got in the top 3 with a pretty good mark! Just study hard and if you fail your half-yearly miserably then consider but don't as you will go better than you think you...
I bet everyone went well in this test and gets the marks they have desired for so don't worry! Just focus on your next exams and ace them! Good luck everyone!