Desperate year 11 on sixth form applications!!!

My head of year recently came up to me about being my reference.One of the points is having an attendance over 90% which i dont have!As of currently my attendance is barely 80% due to extenuating circumstances that made me unable to go to school.Despite this i managed to get a predicted grade average of 8.7 aswell as some decent supercurriculars.Im really worried that solely because of my attendance ill be unable to go to my desired sixthform which is literally my number 1 choice because the distance is far more accesible than the school im at now.I dont know what to do and im seriously panicking!!!