Simply replace the unfilled areas such as "" and "[date]" with your information.
I am formally requesting a leave of absence from [date] through [date] for personal reasons.
I would like to keep this confidential, and I am asking for your understanding in this matter. I feel that my long-term success with this organization will be impacted if I don't address matters in my personal life now.
Please advise me of your decision as soon as possible, and thank you for understanding. If you would like more information, please don't hesitate to ask.