Exam swap between twins

I am one of a pair of identical twins. My brother is brilliant in maths, and I am better with languages. In our recent internal school exams, we swapped places. He sat my maths paper under my name, and I took his language paper under his. We even exchanged student IDs. Nobody seemed to notice at the time, but now I am plagued with guilt and fear. These were not national exams, but I am scared of being expelled or worse if the school finds out. What could happen, and is there a way to fix this before it is too late?
PF, Dar es Salaam

This sounds like a movie script! Very interesting what you did.

Impersonating another individual during an examination is considered a serious violation of school regulations and, in the case of national examinations, may constitute an examination offence. National Examination Council Examination Regulations, 2015 prohibit cheating in examinations, and, in case of a candidate, cheating will have his/her examination results nullified. You have noted that these were not national exams. However, even during internal assessments, educational institutions are mandated to uphold academic integrity, and violations of school regulations can lead to disciplinary actions such as suspension, expulsion, or official notation on academic records.

Since an investigation has not yet commenced, as stated, it is advisable to seek confidential legal counsel before revealing any details. You may also consider making a voluntary admission to the school facilitated by a legal advocate or student representative. Your willingness to come clean may serve as a mitigating factor for serious consequences. We believe the school will have guidelines and rules on how to fix this situation. Possible remedial actions may involve retaking affected exams. Consult your lawyer for further guidance and avoid conduct that is not acceptable in the future, as some actions may amount to criminal offences with more serious consequences on your life. Of course the other option is to keep quiet, which we wish to not comment on.