I think that I had 14 from the 22nd of May to 24th of June, though they were mostly Maths modules, so I'll tell you how I approached it.
I did all of the knowledge and textbook questions well before the exam so there wouldn't be any last minute cramming.
I'm not one for rigid timetables, so I just made a simple one in terms of months what modules I should have finished and when by. This was easy to pick for me as I aimed to finish 2 A2 Maths modules, 3 AS FM modules and 1 Physics/Chemistry module each, so what I was going for was at least half of the modules for each A-level. As you have 17 it's not an even number, but I'd suggest aiming to finish learning 1 or 2 of the FM modules and all of the modules for your other AS subjects. Then do the odd past paper here and there and aim to finish what you have left by April/March. Also look for any significant gaps in your timetable to leave past papers till.