Please i am in desperate need of help i was caught plagiarism?

In my experience, honesty is the best policy. Explain but don't tell your story. If they caught you, they want to know why you won't do it again, NOT why you did it. Don't tell that side unless they ask. In your letter explain that the mistake was due to extreme stresses that have since ped and will not be repeated. " I have been exposed to extreme stresses due to my immediate family and have since removed myself from that situation and will not submit myself or my academic future to any such problems in the future. I greatly appreciate your understanding and fully commit myself to the true academic excellence that I know I am capable of. Thank you for your understanding and compion!"