If they stop talking to you because you report these people for bullying you, then they aren't true friends.
You could try and report the video to Facebook and they may remove it for you.
You should talk to someone, a teacher, counsellor, family or a family friend.
It's horrible to go through bullying alone, I suffered all the way through school in silence and ever since I have wished I had told someone.
Stay strong! You can get through this.
PM me if you ever need to talk, my inbox is always open to people who want my help
<3