I have been saying this prayer ever since I was about 13 years old. I got it from a little book of prayers that my Great Aunt Eileen gave to me on my Confirmation. I thought I should write it down for posterity, in case I ever forget it. It goes:
O My God,
I adore you and I love you with all my heart.
I thank-you for having created me, having saved me by your grace, and for having preserved me during this day.
I pray that you will take for yourself whatever good I may have done, and forgive me for whatever evil I may have done.
Protect me this night and may your grace be with me always and with those I love.