Well Bekki your grades are well above average! In my GCSEs 20 years ago I got only 1 A, 4 Bs, 3 Cs abd two Ds, But I had severe bullying throughout school, lost confidence, developed anxiety (which I still have) got dumped in to a behavioural unit and ended up being mostly self taught from books because the teacher I had was not trained to GCSE level. Moved to college, passed the BTEC national diploma in science, worked in a factory for 10 years then discovered youth work training. Been doing it for 7 years.
As we get older we discover more things to worry about, not only getting high marks, like family, children, houses, etc. your grades and experience are phenomenal, so relax a bit and enjoy what you have and what you are doing. I'm sure you will ace the 2:1...yeh A levels didn't work for me either