Dear {Recipient}
Please accept my deepest apologies for my mistake in regard to {state mistake}.
It was not my intention to create such an awkward and embarrassing situation for {you, institution, the team, company, etc…}.
If there was any good that came out of this unfortunate experience, it is that I have grown and learned alternative approaches to these situations.
Please feel free to let me of your thoughts and concerns over this matter. You can reach me at {email, phone number}.
Sincerely,
{Sender}
{Sender}
