Is it possible for me to repeat sixth form?

I am currently in year 13 at sixth form however due to missing a large amount of school during year 12 and the beginning of year 13 because of uncontrollable circumstances it is unlikely I achieve the grades I know I am capable of. As well as this I did not apply to university due to my poor predicted grades. I therefore believe it would be beneficial for me to repeat sixth form. The reason I would prefer this to just repeating year 13 is that most of the learning I have missed is year 12 content. As well as this, not learning the year 12 content has put me at a sizeable disadvantage when learning the year 13 content. I made an inquiry about this to a sixth form in my area (not the one I currently attend) and was told that legally this is not possible as I would be starting sixth form at the age of 18 which is supposedly not allowed. However, a friend of mine claims to know someone who repeated year 12 at the very same sixth form I made my inquiry to despite being 18 at the beginning of the academic year . Whilst they were going from year 12 to year 12 rather than year 13 to year 12 their 18th birthday was September the 2nd making them 18 upon entering year 12 and therefore this reasoning doesn't seem to hold. My birthday is the 26th of August so upon entering year 12 I would only be a week older than this student was. So, can I re-enter year 13?

I am currently in year 13 at sixth form however due to missing a large amount of school during year 12 and the beginning of year 13 because of uncontrollable circumstances it is unlikely I achieve the grades I know I am capable of. As well as this I did not apply to university due to my poor predicted grades. I therefore believe it would be beneficial for me to repeat sixth form. The reason I would prefer this to just repeating year 13 is that most of the learning I have missed is year 12 content. As well as this, not learning the year 12 content has put me at a sizeable disadvantage when learning the year 13 content. I made an inquiry about this to a sixth form in my area (not the one I currently attend) and was told that legally this is not possible as I would be starting sixth form at the age of 18 which is supposedly not allowed. However, a friend of mine claims to know someone who repeated year 12 at the very same sixth form I made my inquiry to despite being 18 at the beginning of the academic year . Whilst they were going from year 12 to year 12 rather than year 13 to year 12 their 18th birthday was September the 2nd making them 18 upon entering year 12 and therefore this reasoning doesn't seem to hold. My birthday is the 26th of August so upon entering year 12 I would only be a week older than this student was. So, can I re-enter year 13?

Hi don’t worry you can definitely retake a year I know plenty of ppl that retook at the age of 18, u can try search for another college to go to perhaps ?