Dropping out of 6th form

Maybe starting again at a different school or college would help - new people, new start, might be more motivated?

You could always start next year when you've grown abit wiser I done that, took a year off to do my own stuff before coming into sixth form.
But if you hate the school so much and don't want to be there for two years you can study as a private candidate and/or get a private tutor.
The negative is you obviously wasting a year of your life even if you do get a job in this climate you'll just be thinking about education and school so it's just downhill.
I say if you can live out the remainder of your AS-levels and stick it out then transfer to another sixth form/ college in your A2.

Hope this helped.