Jhakka has posted a guide on this community. You can find the thread at the top of the English Extension 2 main forum.
Apart from that, there are a few in the BOS community resources that you may use as examples and some overall EE2 help guides in a summary format.
Also, the examples you have read in the Young Writers Showcase books provide fantastic structures that you can use, though you should change it to flow with the type of prose-style essay you use for your reflection statement.
The EE2 syllabus provides the points that should be addressed in your reflection statement, all addressed in Jhakka and co.'s guide. The markers comments on the BOS website tell you what not to do as well.
You have left it late and you should be stressing. Use this stress as energy to finish it to become good enough for submission.
Good luck. You are going to need it.
