S200 I agree with S200. You need to stop telling yourself that you "can't" do better at English or "I just can't be good in English". Like mindset is everything, and you're almost setting yourself up for failure by saying you "can't improve much". Who said you can't? Even if it's just small wins, that's amazing! It just takes hard work, persistence, and a growth mindset. Trust me, your mindset is so important. You should be realistic, but not lose faith. Like "I might not get an A on my next sac, but I can at least aim to make a small improvement/increase my marks a little, and with time, I might be able to aim for a B". With time, and baby steps, you can improve! Don't give up!
And yes, I'd maybe look at extra resources or tutoring if that's a valid option. Extra help along the way can be great (coming from a tutor myself, although not English, tutoring can really help build your confidence and improve...but mind you it's not necessary to boost your marks).
You've got this!!!