Carry on with A2 and resit your AS exams next year, but don't apply to university this year. Then next August when you get your results, you will know which universities you can apply to depending on what you got. Then apply for university next autumn for courses starting in 2017, and take a gap year over the 2016/2017 year (make sure you do something worthwhile!) Your A Levels will still be taken over 2 years this way. I'm sorry there's no point applying for university this year as you won't get into the kind of institutions you want to go to with an E in history.