EPTFirst and foremost, be sure that BEFORE the exam you know 2 things, one, try drinking fucking coffee. I can't stress this point enough, if you are not used to drinking coffee than it will have a different effect on you than on an avid drinker, the less you drank in the last few years/months the better you will fell after drinking ( if you get used to drinking every morning your brain simply adjusts to it ). This might not apply for you, but for someone like me it can be the difference between a 5 and 9-10 at a math exam.
Two, if you can cheat... cheat. Now you might know this already, but you said your parents were very strict so i shall mention it. There are certain things ( non-cannon name for substances at chemistry, certain names at biology... etc ) that most teacher themselves are not concerned with and if you have a chemistry exam that is based 100% of problems than the teacher will likely ignore the students talking for 10 secs or looking at the phone for 5, so make sure to know the "bounds" of the supervisor and don't try to copy what you can't copy but always try to avoid spending a lot of time learning what you know you can copy.
As far as studying goes... learn at your own peace and learn what you like. If you really like a certain subject and are good at it than focus on it, if you can obtain very good results at something it's very likely that it will improve your attitude and also the attitude of your teacher.
Most of the time you will have a very short period where you both motivated enough to study efficiently, try to "spot" those periods and just study than. Lastly, never pass something that you didn't understand. If you know 95% of shit very well and 5% you don't than that 5% is bound by Murphy's law to come an bite you in the ass. The worst felling is to have studied almost everything than still get a bad grade because you didn't knew everything. Ether be on your A-game in terms of study or simply don't study at all and at least your will go into the exam with no stress because you are not as invested in it ( this, ofc, doesn't apply to exams that are required for you to pass ).
