I study A Level psychology and biology, and BTEC L3 National Foundation Diploma in Sport. During Summer I focused solely on BTEC work and completed all 5 units of coursework in that time, so I'd recommend working on BTEC work pretty much solidly during weekends and school holidays (especially rn because we can't exactly go out or anything so less distractions). Essentially, i did the whole BTEC course in 6 weeks and now just have 2 exam units in Jan which are no hassle at all. Just keep in frequent contact with ur teachers and have something to aim for which will motivate you.