Coming from only doing Core science and additional science at GCSE, A level physics can be very difficult. But as said multiple time. Just have to get on and do it. There are aspects of physics that i can't stand, like mechanics and further mechanics, as its just suvat and momentum constantly. I mean I've lost interest for the subject, it still fascinates me, but if it werent for me wanting to go Uni, i would've stopped by now. Just think what you want to do in the future, and if physics is needed. BTW would recommend maths A level to be done alongside physics, as i'm the only one not doing it in my class and alot of the maths gets brushed over since they already know it, meaning i have to go and do extra work outside of the lesson. Last thing, if you do edexcel, write up your core practicals straight away, it's a big mistake to not!