Is A-levels tough you asked? Well, my answer will be no, AS LONG AS you put your heart to it, it will definitely not be a hurdle to you.
For me, I was a science student when I was studying A-levels with subject combination of Biology, Chemistry, Physics and Mathematics. There is definitely ups and downs throughout the journey, but trust me, as long as your goal is clear, with good time management and hard work to your studies, it will pay off.
Many students suffer from juggling too much subjects, for me it's important that you need to have a least sense of passion to the subject you are learning. For example, Mathematics, you need to be at least not afraid of numbers to do it. MENTALITY IS THE KEY. You need to know that you can do it and you will do it.
Being an A-levels student means that you will need to have GOOD TIME MANAGEMENT SKILL, click here to see my Life Of Being An A-levels student post. Well-balanced time for academics and also leisure, it is very essential for your life as a student. You need to know, WORK HARD, PLAY HARD.
Another key of sailing through A-levels will be SETTING YOUR PRIORITY RIGHT. I won't say that hanging out with friends and doing leisure activities are a waste of time, no they aren't, but then this will link back to your main goal of the day, what is that you want? Hence, being well cleared that you know your GOALS, then strive to it, and you must set the priorities right.
Don't forget, nothing can come out just a night, you definitely need to put in time and effort, only success will comes to you.