Help resits

I got my A-level results yesterday and barely passed, I got accepted into my firm choice university, but I dont know how because I was way below there requirements. In AS first year of college I got straight A Grades, close to 100% in almost every exam, but for A2 I completely failed, got 2 A, 2 E grades and 2 U Grades, On the end it balanced out and gave me triple high C grades.

Im planning on resitting 5 A level exams in total, 3 in the first year of university and 2 in the second year because I know I can get near enough 100% in them

I failed my A2 the first time round because of Personal family reasons, parents were going through divorce, courts, social services and alot of other stuff and I just couldnt cope with it because of what was going on. It all started close to March 2014 and is still going on, but Im okey with it now

I wanted to ask how I could resit my A-Levels in my first year of Uni?
Do I enter as a private candidate in my old college?
will they let me enter?
Also should I resit them? , my first year of uni ends in may 2015, my A levels resits if I get accepted would be near the end of june and start of july
Also lastly why did my university accept me with triple C, Im sure they dont know about my circumstances because I didnt tell my college