i need help

my finals are in 10 days and i literally dont know how i should be organising my time or studying like im too stressed to even start, i keep thinking like, should i study a few of 3-4 subjects a day or stick to a single subject a day? but then i feel like ill forget the subject after a few days, or i keep feeling like ill run out of time, also its so hard to concentrate for a couple of hours at a time