Yeah I'm in Year 11 too and the stress is getting unreal, especially with having to study so many different subjects.
I really can't say I'm an expert at revision or anything, far from it in fact but I guess I can tell you what I've been doing to maybe spark some sort of inspiration...
Also you may take different subjects to me so i don't know how useful this will be:
So maths I only really do practise papers, mark them and take a record of what you get for each paper. If you run out, you can use websites with papers dating back to 2003.
Chemistry and physics I just read some revision guides as it is mostly understanding of topics, then practise papers to master the whole exam technique.
More content based subjects like biology, geography and latin (the literature part) make sure you have notes on everything, even if it's classnotes as long as you'd be happy revising from them. Then practise papers, because again, exam technique
I take music as well and I just make mindmaps of the set works and just listen to the pieces a lot and pretend to commentate over them to revise. I don't do so past paper questions really because we do ours in class mostly.
And about motivation, I really don't know I go through ups and downs and all I can say is during those short peaks where you feel super motivated, make the most of it!
Wish you the best of luck
I'm sure you'll do great. Have a good week.