How do i say sorry? Im in deep, please help....?

So i cant go into complete detail, but basically i slandered a bunch of girls and a couple guys, and i got suspended for 3 days. Starting tomarrow, but it was indirect slander, i didnt mean to hurt anyone, it was just supposed to be between a select group of people and it got out. I am not required to write apologies but i know i have done wrong and i know to help myself and to start over i need to bring closure. How do i start off? How do i even begin to say how sorry i am? Im in deep guys please help, i dont know if i can go on with my life if i cant make my apology truely meaningful. I am to the bottom of my heart sorry. please help!