Moving sixth forms at the end of first year? Will I have to start all over?

I have unfortunately had a persistent illness which has really affected my attendance in sixth form ans because of this I don't feel like I've settled in and my grades could be better. But I worked super hard this year and have a lot of knowledge from the courses and redoing it all would really set me back for what I want to do in the future. I can't find any colleges that do my three subjects: English lit, history and religious studies all on the same exam board. However I would be willing to learn the content that I've missed and I know I will be committed into learning it all. I'm not doing any AS exams all of them are at the end of next year. Will it be possible to continue at at a different sixth form even if the exam boards aren't the same?