Your main issue probably won't be your grades (which seem very good - especially if you finish with AAB at A2), but your profile of work experience. I know that teaching courses often expect a good amount of relevant work experience in schools, and this is something that you might be able to address during your A2 year.
Your previous health problems will not disadvantage your application - and if you are upfront and say that your GCSEs aren't as good as you could have done because of your CFS, then this should be something considered. As long as that D isn't in maths, english or sciences, then I wouldn't be too concerned. If it is - then you know that you'll be looking to retake this year.
Do you have any ideas about where you'd like to apply? You might just want to check with individual courses that your selection of A Level subjects is deemed appropriate for the course. Based on your academic potential indicated by your A Levels, I should think that you stand a pretty reasonable chance at quite a lot of places. Good luck!
When you say primary education courses, are you looking to gain QTS or work as a HLTA? Have you fully recovered from cfs? Primary is very full-on and demanding. You may be choosing a career that will endanger your health further.
I'm looking to apply to primary education courses starting in sept14. I'm currently 2 years behind as I have/had cfs and therefore I have dissappointing gcses- A, 5B's, C and a D. I also have ICT grade A at A2l and AAB in business studies, economics and health and social care at AS and will be take the first to till A2 and hoping for and A or B grade. Do you think that I will get any offers and which unis do you think I should apply for. Thanks