you've recognised the mistake behind your mistake of leaving things too late... that's the first step towards learning :)
Now all you've got to do is use these 17 days to catch up and it can be done Inshaa'Allaah.
1. Print a calendar (
http://www.calendarsthatwork.com/cat...e&sid=G2FnbcjD)
2. Put in your exams
3. Then on a separate sheet, make a plan in a table format. IN your first column have Subjects to revise, in the second, sub-topics (Put the subjects you have first as priority so you revise them first).
4. In the third column, put in a time you will dedicate for revising that sub-topic e.g.
Biology-Respiration-2 days
5. Have a final column for a tick/check list e.g.
Biology-Respiration-2 days-COMPLETED
Now find the ways that work the best for you and follow the plan diligently.
Some good ways to revise are:
1. Mind Maps
2. On coloured paper
3. Using flash cards
4. Writing things in boxes etc
5. Using past papers
6. Getting someone to test you
You could also stick all your posters on your wall not only to help you go over it but also to give you a sense of achievement.
Above all.. have faith...be proactive and succeed!! I wish you all the best. May Allaah make easy your affairs-aameen :)