How can I do lots of homework efficiently?

im in 11th grade and i got transferred up to honors cles cause the teachers thought i wasnt doin anything in regular and holy shiz i got piled this weekend. gotta read civil disobedience and do like a 10 page journal by thursday, a 6-10 page lab report, read 350 pages of the invisible man in 2 weeks and journal that, read a chem chapter by wednesday, and study for academic decathlon which is like 5 hours of hw, and i got 300 word (not an exaggeration) vocab test in 3 weeks and IT KEEPS COMING... i just did homework for 2 hours and i barely got anything done. its like after sitting down for 10 mins, i fidget around and cant concentrate and start blanking out. how can i study efficiently?? help me please