question about iqama renewals for 18 year olds.

Assalamualaikum, I had a question about those people who have had their iqama renewed after they turned 18, I'm asking because my father told me that once I turn 18 unless I prove that I'm studying I have to be 'seperated'. The thing is that I'm done with my A-Levels but haven't started uni yet as applications aren't open yet. So in my case what can I do? Can I get a letter from my school stating that I'm still enrolled/studying?