Hi Elyas,
I was freaking out myself not that long ago, I find this book to be perfect -
Books | Air Pilot's Manuals - Thom | BTT080 | APM 8 PPL Question & Answers to accompany the Air Pilot's Manuals
obviously CAA air law will not work for you, but other sections cover absolutely everything you need to know, after every section there are really good explanations that put everything into place. Good luck and calm down - go through lots and lots of question banks, study subjects that you don't understand - don't just learn the answers