Hi! I honestly think it's amazing that you're trying your best given the circumstances, for maths I'm going to assume you're doing the foundation paper, and what you're currently doing is probably enough, clear up any misunderstandings in topics with your teacher. For English I'd recommend reading through the examiner reports as they tell you exactly what examiners are looking for in each question, as well as provide sample responses. (They can be found on the exam boards website, just look up your course). The grading this year is supposed to be more generous so I think you have a decent chance of getting those 4s! All the best of luck!