I am in year 12, just finished my first term if sixth form. But it isn't going very well

I took Art as an A-level and i am really struggling, I got an A at GCSE but i seemed to of lost all the talent i had :/ i haven't enjoyed any of my courses yet and I'm stressing out every day. I am thinking about dropping it because it is affecting me badly. But i don't want to :/ I haven't done any work in 3 weeks because it all hasn't been good enough. I am also thinking about dropping Biology because i am finding it extremely difficult!! i can't keep up in class and got a U grade in my mock

So i can't drop both so what do i do? I'm thinking about dropping out of sixth form all together as i am really not happy there!! Any advice guys? Appreciate it.