Im failing and want to leave sixth form

(Original post by Hu638ss)
Since I started sixth form in September I have slowly been going downhill academically as my hate for my sixth form kept on growing. I am a good student with GCSE results of 7 As and 4Bs and I've really enjoyed secondary school. However I now attend a top sixth form and I've been struggling to keep up with the work. I study chemistry, biology and economics (I was good at these subjects in gcse). I feel like my sixth form is demanding too much from me e.g. I was given 100 hours of work to do in total over this holiday. It's causing me to stress out so much that I feel like I'm just sinking.
I have also been struggling with school work and exams because I feel like I've been left behind by the rest of the students who are mostly straight A* students. I havent even made many friends and I dread going to class which worries me about my future in this sixth form.
I really want to leave this sixth form for another one but I've been told by many that I can't start until next September which is a long time. Although I'm fine with this I don't think that my parents agree with it as they think I would fall more behind. All I want is to be given the chance to have more freedom in sixth form without the need for endless homework everyday and detentions so that I can put my time into actually revising than stressing about excessive hw. Sorry for the long post but I feel like I'm stuck in a hole and I need some advice on what I should do to get out of it.