22/23 is great, remember your practice essays are marked harder because you have had time to edit them etc etc. But the actual exam answer will be marked as a first draft and like exam pressure will be taken into account. (well that's what my teacher said) and i am sure if you are getting 22/23's you will probably hit a 24/25 in the exam...so i think you don't need to worry
Like goan_crazy said you need to to more of what the key word says eg. evaluate, assess, etc. So just keep doing that
throughout your essay and that may help too.
GOOD LUCK!